Sora no Otoshimono

Sora no Otoshimono (そらのおとしもの), also known as Heaven's Lost Property, is a Japanese manga series written and illustrated by Suu Minazuki (author of Watashi no Messiah-sama). The plot revolves around Tomoki Sakurai, a highly perverted young man struggling to live a peaceful life. His already-difficult life worsens when he encounters a fallen Angeloid named Ikaros, who soon becomes his servant.

Sora no Otoshimono began monthly serialization in the May 2007 issue of manga magazine Shōnen Ace. The first tankōbon was released by Kadokawa Shoten on September 26, 2007, and as of October 2010, ten tankōbon have been released. An anime adaptation produced by AIC aired in Japan between October and December 2009, with a second season running from October to December 2010. The anime is licensed in North America by Funimation Entertainment, who will be relasing the series in 2011.

Plot
Tomoki Sakurai is a young man whose motto is "Peace and quiet is the best", but he finds it difficult when he has to put up with a next door neighbor with a killer karate chop, an eccentric scientist bent on discovering the "New World", and a borderline sadist. One day, while he was witnessing a strange anomaly in the sky, a UMA (Unidentified Mysterious Animal) falls from it. What falls from the sky is an Angeloid named Ikaros, who soon becomes Tomoki's servant.

Main characters

 * Tomoki Sakurai (桜井 智樹)
 * Tomoki is ths series' main protagonist, who wants nothing more than a peaceful and quiet life in town. However, his life is forever changed when he meets Ikaros and the other Angeloids. While being shown to be a shameless pervert (to the point of creating peepholes via improvised pipe periscopes to every peeping spot all over town ), he is usually a kind and sincere person. Tomoki was heavily influenced by his equally perverted grandfather, whose dream was to make out with every woman in the world, but could not do so before his death. He appears in Tomoki's flashback to give him (albeit perverted) advice, which always seems to help the latter in dire situations.
 * Tomoki is ths series' main protagonist, who wants nothing more than a peaceful and quiet life in town. However, his life is forever changed when he meets Ikaros and the other Angeloids. While being shown to be a shameless pervert (to the point of creating peepholes via improvised pipe periscopes to every peeping spot all over town ), he is usually a kind and sincere person. Tomoki was heavily influenced by his equally perverted grandfather, whose dream was to make out with every woman in the world, but could not do so before his death. He appears in Tomoki's flashback to give him (albeit perverted) advice, which always seems to help the latter in dire situations.


 * Tomoki frequently experiences a dream involving him meeting an angel, who takes off into the sky to his disappointment. This was later revealed to be a gateway between the human world and the world of Synapse. Tomoki has shown feelings for Ikaros and Nymph and takes on the task of helping Ikaros become more human. He has also tried to break the Angeloids' tendency to obey their masters' orders completely by letting them do whatever they want, giving them a great degree of freedom to make their own individual decisions. While he constantly laments that his idealistic world of peace and quiet is ruined by the appearances of the Angeloids, he admits that he does see them as family and enjoys their company.


 * On rare occasions, he transforms to a female alter-ego called Tomoko (智子) through a quantum converter made by Synapse, and mainly uses this new form to blend in with the other girls so he can peep on them unnoticed. However, if Tomoki becomes sexually stimulated for too long while as Tomoko (or any other object), the transformation will end and the converter will short out. A small note is while all of the other characters are drawn in their original parameters, Tomoki is mostly drawn in super deformed parameters, with the only times being drawn in his original parameters is when he is serious or feels relaxed.


 * Ikaros (イカロス)
 * Ikaros is a "Pet-Class Angeloid, Type Alpha" who becomes bonded to Tomoki at the beginning of the story, which is symbolized by the invisible chain leading from her collar to Tomoki's hand. She displays a very submissive, melancholic personality and is completely subservient to Tomoki's wishes. Ikaros possesses the ability to grant seemingly any wish through the use of several techno-magical cards. Despite her passive appearance, Ikaros has displayed moments of aggressiveness whenever Tomoki's life appears to be in danger. She weighs 48 kilograms (106 pounds), stands at 162cm (5 feet 3 inches) and her wing type is listed as "Variable". Her "Variable" wings are extremely valuable and are highly desired by Synapse. While she begins the series with a poor grasp of human emotion, she eventually begins to acquire emotions and begins to fall in love with Tomoki. The reason for this is because she has high battle and processing capability, but has low emotional control as a result. She has been shown to be willing to sacrifice herself if it means ensuring the safety of Tomoki. Ikaros is also shown to do anything that will gain Tomoki's approval, even if it's a questionable act (normally involving Tomoki's perverted schemes) on Tomoki's part; she admits that as long as Tomoki is happy, she will also be happy as well.
 * Ikaros is a "Pet-Class Angeloid, Type Alpha" who becomes bonded to Tomoki at the beginning of the story, which is symbolized by the invisible chain leading from her collar to Tomoki's hand. She displays a very submissive, melancholic personality and is completely subservient to Tomoki's wishes. Ikaros possesses the ability to grant seemingly any wish through the use of several techno-magical cards. Despite her passive appearance, Ikaros has displayed moments of aggressiveness whenever Tomoki's life appears to be in danger. She weighs 48 kilograms (106 pounds), stands at 162cm (5 feet 3 inches) and her wing type is listed as "Variable". Her "Variable" wings are extremely valuable and are highly desired by Synapse. While she begins the series with a poor grasp of human emotion, she eventually begins to acquire emotions and begins to fall in love with Tomoki. The reason for this is because she has high battle and processing capability, but has low emotional control as a result. She has been shown to be willing to sacrifice herself if it means ensuring the safety of Tomoki. Ikaros is also shown to do anything that will gain Tomoki's approval, even if it's a questionable act (normally involving Tomoki's perverted schemes) on Tomoki's part; she admits that as long as Tomoki is happy, she will also be happy as well.


 * As the story progresses, it is revealed that Ikaros is not a "Pet-Class" Angeloid, but is actually a "Strategic Battle-Class" Angeloid and is the most powerful of the First Generation Angeloids. She takes little physical damage when she is shot, can fly to speeds up to Mach 24, and is able to withstand water pressure better than most submarines. In the past, she was called the Uranus Queen (ウラヌス・クイーン) and terrorized Synapse due to her immense power and battle capabilities. She was originally sent to Earth as a weapon of judgement and is responsible for destroying the Tower of Babel.


 * Ikaros is seen to be with the only Angeloid who has a "Battle Mode". When she activates her battle mode ("Uranus Queen Mode"), her wings are engulfed in bright light, her eyes become red, and a halo appears over her head. Ikaros can generate a nigh-invincible energy shield called Aegis (イージス). She also possesses several powerful weapon systems: Artemis (アルテミス), a series of multi-directional homing energy projectiles fired from her wings, and Apollon (アポロン), a bow that can fire energy-charged arrows capable of obliterating a country in a single shot. She also possesses the ability to summon and control a third weapon called Hephaestus (ヘーパイストス), which is part of an anime-only weapon system called the Uranus System (ウラヌスシステム), which vaguely resembles a massive cloaked spaceship. Both were first used in battle against the twin Gamma Harpies, but only the Hephaestus cannons were shown and dwarf the Harpies' Prometheus in firepower and size. It was later seen again in the second season in full scale against the second-generation Angeloid Chaos, but it was later destroyed after Ikaros took Chaos to the bottom of the ocean with it. A running gag in the series involves Ikaros occasionally seen holding a watermelon, a fruit she curiously takes an interest in; this leads her to eventually grow a patch of watermelons in the garden. Ikaros's name is a play on the Greek mythological character Icarus, whose fate (falling from the sky) can be related to Ikaros's introduction into the storyline.


 * Nymph (ニンフ)
 * Nymph is an "Electronic Warfare Angeloid, Type Beta" (電子戦用エンジェロイドタイプβ（ベータ）) who mysteriously appears in Tomoki's house. She is condescending towards humans, whom she refers to as "bugs"; this is no doubt a result of her former master's constant belittling of humans or as he calls them, "Downers". After she spends time with them, she realizes the error of her ways and starts to treat them as equals. She weighs 29 kilograms (63.8 pounds), stands at 139 centimeters (54.6 inches or 4 foot 6 inches), and her wing type is listed as "Not Variable" and "Stealth". Because of this, Nymph can completely conceal her wings unlike Ikaros, who can only retract her wings to a certain point. She is originally sent to return Ikaros to Synapse. However, because she is less powerful than Ikaros, she is unable to do so. Her master later implanted a bomb within her collar that will explode after the green bars on it disappear, which was later disabled from the teamwork of Tomoki and friends. She soon develops feelings for Tomoki and later confesses to him. After the Gamma Angeloids attempt to kill her, she betrays Synapse and assists Tomoki, and moves into his home. Her wings were torn off by the Gamma Angeloids, but were regrown when she accepts Tomoki as her new master. However, in her delight at having her wings regrown, she forgot about the Imprinting process and finds it extremely difficult to broach the subject to Tomoki; by her own admission, it is not a difficult task, but she feels embarrassed enough to eventually back out of asking. Eventually, Nymph asks Tomoki to Imprint with her, but he refuses, saying that he wanted her to live freely. She is named and modeled after the nature spirits of Greek myth.
 * Nymph is an "Electronic Warfare Angeloid, Type Beta" (電子戦用エンジェロイドタイプβ（ベータ）) who mysteriously appears in Tomoki's house. She is condescending towards humans, whom she refers to as "bugs"; this is no doubt a result of her former master's constant belittling of humans or as he calls them, "Downers". After she spends time with them, she realizes the error of her ways and starts to treat them as equals. She weighs 29 kilograms (63.8 pounds), stands at 139 centimeters (54.6 inches or 4 foot 6 inches), and her wing type is listed as "Not Variable" and "Stealth". Because of this, Nymph can completely conceal her wings unlike Ikaros, who can only retract her wings to a certain point. She is originally sent to return Ikaros to Synapse. However, because she is less powerful than Ikaros, she is unable to do so. Her master later implanted a bomb within her collar that will explode after the green bars on it disappear, which was later disabled from the teamwork of Tomoki and friends. She soon develops feelings for Tomoki and later confesses to him. After the Gamma Angeloids attempt to kill her, she betrays Synapse and assists Tomoki, and moves into his home. Her wings were torn off by the Gamma Angeloids, but were regrown when she accepts Tomoki as her new master. However, in her delight at having her wings regrown, she forgot about the Imprinting process and finds it extremely difficult to broach the subject to Tomoki; by her own admission, it is not a difficult task, but she feels embarrassed enough to eventually back out of asking. Eventually, Nymph asks Tomoki to Imprint with her, but he refuses, saying that he wanted her to live freely. She is named and modeled after the nature spirits of Greek myth.


 * As an Electronic Warfare-type Angeloid, she has the ability to hack computer systems better than any other Angeloid. She is also capable of hacking other Angeloids as well as humans. She can also fire a high-powered energy beam from her mouth called "Paradise Song" (パラダイスソング). When being hacked by Hiyori, Nymph displayed a new ability, a "fundamental particle-jamming system" called Aphrodite (アフロディーテ). When using this, she becomes immune to hacking and her wings grow into a butterfly shape. However, using it generates a lot of heat, causing her to enter cooling mode as a result. Nymph has high processing capabilities and has high emotional control, but as a result she is low in raw power. She also has the most powerful radar of the three first-generation Angeloids (Ikaros has stated that her own radar's proficiency cannot be compared with that of Nymph even though she was wingless at that time, though it was stated by Nymph herself that her radar was a lot weaker at the time her wings had not grown back ). Nymph is shown to have a sweet tooth; her appearances mostly show her snacking on chips and other snacks, and is shown to have a penchant for watching soap operas. She refers to the other Angeloids by their types rather than their names (i.e. Ikaros→Alpha).


 * Astraea (アストレア)
 * Astraea is a "Close-Combat Angeloid, Type Delta" (地戦闘用エンジェロイドタイプΔ（デルタ）) sent by Synapse to kill Tomoki after he violates one of their rules. She is somewhat an airhead and has limited intelligence due to having low processing power, making her somewhat the dumb blonde of the group. She weighs 48 kilograms (105.8 pounds), stands at 159 cm (5feet 2 inches), and her wing type is stated to be "Not Variable" and "Super Acceleration". She is the last of the First-Generation Angeloids to break free from Synapse's control by Tomoki's influence; when she is ordered by the man of Synapse to eliminate Nymph, she breaks off her chain and engages in combat with Chaos. She mostly serves as the series' comic relief, alongside Tomoki. The duo often squabble, but will comically end up agreeing with each other on some absurd conclusion. She refers to Ikaros and Nymph using the senpai honorific since she is the "youngest" of the First-Generation Angeloids, and is named after the Greek mythological figure Astraea.
 * Astraea is a "Close-Combat Angeloid, Type Delta" (地戦闘用エンジェロイドタイプΔ（デルタ）) sent by Synapse to kill Tomoki after he violates one of their rules. She is somewhat an airhead and has limited intelligence due to having low processing power, making her somewhat the dumb blonde of the group. She weighs 48 kilograms (105.8 pounds), stands at 159 cm (5feet 2 inches), and her wing type is stated to be "Not Variable" and "Super Acceleration". She is the last of the First-Generation Angeloids to break free from Synapse's control by Tomoki's influence; when she is ordered by the man of Synapse to eliminate Nymph, she breaks off her chain and engages in combat with Chaos. She mostly serves as the series' comic relief, alongside Tomoki. The duo often squabble, but will comically end up agreeing with each other on some absurd conclusion. She refers to Ikaros and Nymph using the senpai honorific since she is the "youngest" of the First-Generation Angeloids, and is named after the Greek mythological figure Astraea.


 * Astraea also harbors feelings for Tomoki despite often being a target to his perversions. However, despite her lack of intelligence, she does display a good level of common sense in situations where Ikaros would be clueless about. Ironically, she is also regularly found starving due to the fact that she does not know how to hunt or obtain food by her own means, which was shown when she ate a fish bait because she was hungry.


 * Astraea has been described as being the fastest of the Angeloids and having greater close-combat capabilities than Ikaros. However, she is only equipped with close-combat weapons and is therefore extremely vulnerable to long-range attacks. She wields a super-osciliating photon blade called Chrysaor (クリサオル), which can even penetrate Ikaros' Aegis defense system. For defensive purposes, she uses the upgraded version of Ikaros's Aegis shield called Aegis L (イージス L). Although it is more powerful than the Aegis shield, Aegis L can only deflect frontal attacks, unlike Aegis which creates a shield that covers all angles. Also, Aegis L cannot be deployed for long periods of time due to its massive energy requirements.


 * Sohara Mitsuki (見月 そはら)
 * Sohara is Tomoki's childhood friend who lives across the road from him and often goes to his house in the morning to wake him up. As a child, she was constantly ill and thus had few friends. She is continually jealous of Tomoki's relationships with the various Angeloids and generally acts on this jealousy by karate-chopping Tomoki; however, she also does it whenever he's being perverted in her presence. She is also in love with Tomoki and her breasts always seem to be getting bigger. Apparently, her dreams may sometimes involve her and Tomoki being together in many different provocative situations, such as being in the bath together, which suggests she actually likes it when Tomoki is perverted. However, she is shown to get angry when he directs his perverted actions to other girls. Her karate chops are capable of ridiculous cutting power, enabling her to chop through pretty much anything.
 * Sohara is Tomoki's childhood friend who lives across the road from him and often goes to his house in the morning to wake him up. As a child, she was constantly ill and thus had few friends. She is continually jealous of Tomoki's relationships with the various Angeloids and generally acts on this jealousy by karate-chopping Tomoki; however, she also does it whenever he's being perverted in her presence. She is also in love with Tomoki and her breasts always seem to be getting bigger. Apparently, her dreams may sometimes involve her and Tomoki being together in many different provocative situations, such as being in the bath together, which suggests she actually likes it when Tomoki is perverted. However, she is shown to get angry when he directs his perverted actions to other girls. Her karate chops are capable of ridiculous cutting power, enabling her to chop through pretty much anything.


 * Eishiro Sugata (守形 英四郎)
 * Sugata is the leader of the New World Discovery Club (新大陸発見部). He is a scientist of sorts and is currently researching the Angeloids and Synapse with Nymph's help. He lives in a tent near a river and is always seen wearing his school uniform, as he has no other clothes, and continually praises various European explorers such as Magellan and Columbus. He is highly eccentric and has some past involvement with Mikako's family; her servants even call him master. He is also equal on combat abilities with Mikako.
 * Sugata is the leader of the New World Discovery Club (新大陸発見部). He is a scientist of sorts and is currently researching the Angeloids and Synapse with Nymph's help. He lives in a tent near a river and is always seen wearing his school uniform, as he has no other clothes, and continually praises various European explorers such as Magellan and Columbus. He is highly eccentric and has some past involvement with Mikako's family; her servants even call him master. He is also equal on combat abilities with Mikako.


 * Mikako Satsukitane (五月田根 美香子)
 * Mikako is an upperclassman to Tomoki and Mitsuki and the President of the Student Council. She is Sugata's childhood friend, whom she refers to as "Ei-kun", and the heiress of a Yakuza family. She is manipulative, cunning, highly intelligent and somewhat sadistic, usually towards Tomoki. She is forced to take supplementary lessons due to "failing in morals". She also is equal to Sugata in terms of combat abilities. However, Nymph states that she has a grip power of 400kg, which serves to indicate she has a great degree of strength, especially for a normal human. She is the chief mastermind of many schemes in the manga, and Sugata normally enlists the help of Tomoki (and occasionally some others) by persuading him to totally shut down her plans. Many of her schemes are directed to Tomoki, serving to put him in undesirable situations and humiliating him, which suggests she sees him as a toy for her personal entertainment.
 * Mikako is an upperclassman to Tomoki and Mitsuki and the President of the Student Council. She is Sugata's childhood friend, whom she refers to as "Ei-kun", and the heiress of a Yakuza family. She is manipulative, cunning, highly intelligent and somewhat sadistic, usually towards Tomoki. She is forced to take supplementary lessons due to "failing in morals". She also is equal to Sugata in terms of combat abilities. However, Nymph states that she has a grip power of 400kg, which serves to indicate she has a great degree of strength, especially for a normal human. She is the chief mastermind of many schemes in the manga, and Sugata normally enlists the help of Tomoki (and occasionally some others) by persuading him to totally shut down her plans. Many of her schemes are directed to Tomoki, serving to put him in undesirable situations and humiliating him, which suggests she sees him as a toy for her personal entertainment.

Supporting characters

 * Daedalus (ダイダロス)
 * Daedalus is the creator of Ikaros, Nymph and Astraea, the first generation of Angeloids. She frequently appears in Tomoki's dreams, but she flies away leaving Tomoki crying. She comes to his dreams to ask him to help save her. Her name originates from the Greek mythological character Daedalus, the father of Icarus, and her face is obscured in all of her appearances. It is hinted that she may have feelings for Tomoki.
 * Daedalus is the creator of Ikaros, Nymph and Astraea, the first generation of Angeloids. She frequently appears in Tomoki's dreams, but she flies away leaving Tomoki crying. She comes to his dreams to ask him to help save her. Her name originates from the Greek mythological character Daedalus, the father of Icarus, and her face is obscured in all of her appearances. It is hinted that she may have feelings for Tomoki.


 * Hiyori Kazane (風音 日和)
 * Hiyori is a second-year student at Tomoki's school. She has feelings for Tomoki and joins the New World Discovery Club in order to get closer to him. In reality, Hiyori is an Angel who was first seen inside some sort of sleeping chamber when Sugata went to Synapse. The chamber connects her to her body on Earth, which functions like an avatar. Sugata was hesitant on letting her join his club since there are still a lot of things he does not know about what she really is. However, he welcomes her anyway, since her membership will allow his club to receive more funding. Thus far, nobody, except Sugata, Nymph, and Ikaros, is aware of Hiyori's true identity.
 * Hiyori is a second-year student at Tomoki's school. She has feelings for Tomoki and joins the New World Discovery Club in order to get closer to him. In reality, Hiyori is an Angel who was first seen inside some sort of sleeping chamber when Sugata went to Synapse. The chamber connects her to her body on Earth, which functions like an avatar. Sugata was hesitant on letting her join his club since there are still a lot of things he does not know about what she really is. However, he welcomes her anyway, since her membership will allow his club to receive more funding. Thus far, nobody, except Sugata, Nymph, and Ikaros, is aware of Hiyori's true identity.


 * Hiyori got rather embarrassed when it was suggested that she was dating Tomoki, suggesting that while she likes Tomoki, she has not even considered as far as dating him yet, and her presence becomes a source of major discomfort for Sohara, Nymph, and Astraea. This stems from the realization that Hiyori is always kind and caring to Tomoki, while the others seem to only see his "faults". Eventually, Hiyori manages to confess her feelings to Tomoki, which leaves him in shock as no girl has ever confessed to him before. However, her time with Tomoki was cut short when a careless truck driver ran her over, causing her body to disappear and her existence erased from everyone's memories (except the Angeloids and Tomoki).


 * Later on, Hiyori returns as a "Second-Generation Angeloid, Type Zeta" (第二世代エンジェロイドタイプζ（ゼータ）) armed with a khakkhara called Demeter (デメテル), which has the power to control the weather, and has more sophisticated hacking abilities than Nymph. Her master was Nymph's previous master, who turned her into an Angeloid so she could live her "dream" on Earth. Luckily, Hiyori was released from her master's control thanks to Nymph's hacking abilities, allowing her to stay on Earth as a free Angeloid. Hiyori later drops out of the New World Discovery Club, since she already accomplished her goal of getting close to Tomoki (even going so far as kissing him).

Antagonists

 * Man of Synapse (シナプスの男)
 * Also known as the Sky Master (空のマスター) in the anime, he is the sadistic and ruthless leader of Synapse. He finds enjoyment in torturing the Angeloids he owns (both physically and emotionally), seeing them as merely his playthings to which he can do with as he pleases, and discarding them while considering them nothing more than trash. He is condescending towards humans, referring to them as "Downers", a trait that would be later shared with Nymph. Though because of his arrogant ways and believing that the Angeloids that serve him will obey his every order, he always reacts surprised when he witnesses one of them break their chain or go against his orders. He is often seen on his throne with two Angeloids beside him, and like Daedalus, his face is obscured in all of his appearances.
 * Also known as the Sky Master (空のマスター) in the anime, he is the sadistic and ruthless leader of Synapse. He finds enjoyment in torturing the Angeloids he owns (both physically and emotionally), seeing them as merely his playthings to which he can do with as he pleases, and discarding them while considering them nothing more than trash. He is condescending towards humans, referring to them as "Downers", a trait that would be later shared with Nymph. Though because of his arrogant ways and believing that the Angeloids that serve him will obey his every order, he always reacts surprised when he witnesses one of them break their chain or go against his orders. He is often seen on his throne with two Angeloids beside him, and like Daedalus, his face is obscured in all of his appearances.


 * Harpies (ハーピー)
 * The Harpies are a pair of Angeloids introduced as "Ambush Angeloids, Type Gamma" (要撃用エンジェロイドタイプγ). They are responsible for tearing off Nymph's wings and are also guards at the main entrance of Synapse. Their main weapon is a large cannon on their left arms called Prometheus (プロメテウス), which fires white-hot projectiles of 3000 degrees Celsius at 4 km/s. They are named and based on the harpies of Greek mythology.
 * The Harpies are a pair of Angeloids introduced as "Ambush Angeloids, Type Gamma" (要撃用エンジェロイドタイプγ). They are responsible for tearing off Nymph's wings and are also guards at the main entrance of Synapse. Their main weapon is a large cannon on their left arms called Prometheus (プロメテウス), which fires white-hot projectiles of 3000 degrees Celsius at 4 km/s. They are named and based on the harpies of Greek mythology.


 * Chaos (カオス)
 * Chaos is a "Second-Generation Angeloid, Type Epsilon" (第二世代エンジェロイドタイプε) and the first major antagonist of the series. She is ironically the most miniature and child-like Angeloid, weighing 19 kilograms and being only 107 cm in height. Her nun-like garments has the abilility to manipulate her appearance through elaborated illusions, mimicking someone dear to her victim in order to instill turmoil and confusion (as her name implies), as she did against Nymph by taking on the likeness of Tomoki. She lacks wings like other Angeloids, instead sporting a wicked array of bladed, almost organic-like appendages which act as an offensive weapon. Unlike most Angeloids who lack the ability to dream, Chaos has the ability to enter another person's dream, once doing so against Tomoki in her initial appearance. What is most eerie about her is her strange obsession with love, having asked to Tomoki, Nymph, Astraea and Ikaros, often in an extremely creepy manner, what love is, to which Ikaros responded that love, for her, was a sensation of pain in her reactor, obviously in a figurative sense.
 * Chaos is a "Second-Generation Angeloid, Type Epsilon" (第二世代エンジェロイドタイプε) and the first major antagonist of the series. She is ironically the most miniature and child-like Angeloid, weighing 19 kilograms and being only 107 cm in height. Her nun-like garments has the abilility to manipulate her appearance through elaborated illusions, mimicking someone dear to her victim in order to instill turmoil and confusion (as her name implies), as she did against Nymph by taking on the likeness of Tomoki. She lacks wings like other Angeloids, instead sporting a wicked array of bladed, almost organic-like appendages which act as an offensive weapon. Unlike most Angeloids who lack the ability to dream, Chaos has the ability to enter another person's dream, once doing so against Tomoki in her initial appearance. What is most eerie about her is her strange obsession with love, having asked to Tomoki, Nymph, Astraea and Ikaros, often in an extremely creepy manner, what love is, to which Ikaros responded that love, for her, was a sensation of pain in her reactor, obviously in a figurative sense.


 * Chaos first appeared to torture Nymph and then fought Ikaros, whom she initially bested through her illusions, and Astraea. She battled Ikaros again, though this time the latter saw through her illusions and defeated her, sending Chaos into a deep abyssal chasm where she was temporarily incapacitated due to the great water pressure. While there, she wondered about Ikaros' statement to what love means, coming to a dreadful conclusion: love equates to pain. Chaos was left in the abyss, dismembering and devouring fish to—in her own words, grow bigger—and show her "love" to everyone. In chapter 45 of the manga, it is shown that she devoured and absorbed Seiren, the man from Synapse's latest Angeloid, with it revealing that she has a self-evolution program named Pandora (パンドラ).


 * In the final episodes of Sora no Otoshimono: Forte, she returns as an adult, consuming many fishes and birds during her time stuck in the ocean. She then fought against Nymph and Astraea, easily overpowering them until Ikaros' arrival despite her feverish state, but was defeated by Astraea and Ikaros using their upgraded weapons (courtesy of Nymph). She later shuts down, stating that her chest hurts after hearing Tomoki say he should have played with her, in which a padlock-like device was attached to her chain by Tomoki (courtesy of Daedalus). She was then reverted back to her childlike form by Daedalus and returns as a good Angeloid, later becoming Tomoki's Angeloid.


 * Seiren (セイレーン)
 * Seiren is an "Underwater Combat Angeloid, Type Eta" (水中戦闘用エンジェロイドタイプη（イータ）) built by the man of Synapse that appeared in chapter 45 of the manga. Her appearance in the manga was brief, as she was impaled in the back by one of Chaos' wings before being devoured and absorbed by her just after she was ordered by the man of Synapse to kill Tomoki and Ikaros. Her appearance is based on the sirens of Greek mythlology.

Terminology

 * Synapse (シナプス)
 * Synapse is an alternate world located in the skies that is home to the Angels and the Angeloids. It was first introduced in the series as a black hole above Sorami when Sugata did his research on the New World and as a result, believes that Synapse is the "New World" and begins to investigate it, with Nymph aiding him later on. In Synapse, there is a large dome that contains numerous Angels in sleeping pods, which connects them to their real-world avatars. If the avatar in the real world is killed, the people associated with them will have their memories erased, such as the case with Hiyori. Also in Synapse is a large obelisk called the Core, which has its rules written on it.


 * Angeloids (エンジェロイド)
 * The Angeloids are a series of androids built by Synapse. As part of their name implies, they are modeled after the Angels and are programmed to serve their masters. They select their master through a process called "Imprinting", in which a chain attached to their neck collar extends to the chosen master's hand and ties it, connecting it to the collar. The first generation of Angeloids (Ikaros, Nymph, and Astraea) were built by Daedalus, while the second generation of Angeloids (Chaos, Hiyori, and Seiren) were built (or in Hiyori's case, turned into) by the man of Synapse.


 * Each Angeloid is designated with a letter of the Greek alphabet, which descends for every new Angeloid built. Ikaros, the first Angeloid built, is a "Type Alpha" Angeloid, while Seiren, the most recent Angeloid, is a "Type Eta" Angeloid. Each Angeloid has their own unique abilities and powers, which are determined by three factors: emotional control, battle capability, and processing capability. Unlike humans and Angels, Angeloids lack the ability to sleep or have dreams, with Chaos (and presumably Hiyori) being the only exception. Also, Angeliods cannot swim due to their wings being porous to water. The Angeloids' names, weapons, and abilities are derived from Greek gods, mythological figures, or in Chaos' case, words that stem from Greek roots.

Manga
Sora no Otoshimono began monthly serialization in the May 2007 issue of Shōnen Ace. The first tankōbon was released by Kadokawa Shoten on September 26, 2007, with a total of ten tankōbon released in Japan as of October 26, 2010.

Anime
An anime adaptation produced by AIC and directed by Hisashi Saitō aired in Japan between October 4, 2009 and December 27, 2009 on Teletama and Chiba TV, with subsequent broadcasts on KBS, TV Kanagawa, Sun Television, TVQ, Tokyo MX and TV Aichi. English-subtitled simulcasts were provided on the Crunchyroll video streaming website, but was later removed by the publisher. The opening theme is "Ring My Bell" by Blue Drops, featuring singers Hitomi Yoshida and Ikaros (Saori Hayami), while multiple ending themes were used for each episode. Seven DVD compilation volumes were released between December 25, 2009 and June 25, 2010 by Kadokawa Pictures, with limited edition compilations also sold. An original video animation episode entitled "Project Pink" was bundled with the limited edition release of volume 9 of the manga as a DVD on September 9, 2010. The first season has been licensed by North American anime distributor Funimation Entertainment, who will be releasing it under the title of "Heaven's Lost Property".

A second season of the series, Sora no Otoshimono: Forte (そらのおとしもの f （フォルテ）), has been announced on reprinted copies of the manga and ran from October 1 to December 17, 2010. The opening theme is "Heart no Kakuritsu" (ハートの確率) by Blue Drops, while multiple ending themes are used for each episode much like the first season. Crunchyroll will provide English-subtitled simulcasts of the second season as it did with the first season. The second season has also been licensed by Funimation Entertainment and will also stream the series on their video portal.

Film
A film adaptation of Sora no Otoshimono called Sora no Otoshimono: The Movie (劇場版そらのおとしもの) was announced by Kadokawa Shoten in November 2010. The film will focus on the Hiyori arc of the manga, and a 30-second teaser trailer was shown in the post-end credits of the final episode of Forte.

Light novels
A light novel adaptation of Sora no Otoshimono written by Rin Kazaki and illustrated by Minazuki was released by Kadokawa Shoten on February 1, 2010 under its Kadokawa Sneaker Bunko imprint. A sequel to the light novel called Sora no Otoshimono f, written by Rin Kanzaki and illustrated by Minazuki and Ayun Tachibana, was released on October 1, 2010.