Diebuster

Diebuster, known in Japan as Aim for the Top 2! (トップをねらえ 2!) is a six episode anime Original Video Animation (OVA) series created by Gainax in 2004.

The first episode was aired on October 3, 2004, while the final episode was released on August 14, 2005. A movie, officially titled Aim for the Top! & Aim for the Top 2! The Gattai Movie!! (トップをねらえ!&トップをねらえ2! 合体劇場版!!) retells and recaps the end of the first Gunbuster OVA and the finale of Diebuster. It was scheduled to air on October 1, 2006 at the Tokyo Anime Center's 3D Akiba theatre.

Also called Gunbuster 2, it is the direct sequel to Gunbuster, but is animated in a 16:9 widescreen aspect ratio, rather than the 4:3 aspect ratio used in the majority of Gunbuster. It has been licensed for American release by Bandai Visual USA as Gunbuster 2. Additionally a manga adaptation of the series is available in Japan.

Story
''Top wo Nerae 2! Diebuster follows the story of Nono, a country girl who dreams of becoming a space pilot (or to be more precise, 'like Nonoriri,' the meaning of which is revealed as the series progresses) who, due to a chance encounter with an actual space pilot finds herself becoming part of the elite Fraternity''. Made up of teenage pilots called Topless, and armed with quasi-humanoid weapons called Buster Machines, the Fraternity's mission is to protect the people of the Solar System from attack by swarms of space monsters.

The series revolves around Nono's quest to become like Nonoriri, her relationship with Lal'C Melk Mark, the first Topless she meets whom she immediately idolizes (to the point of calling her onee-sama, or big sister), and the hard work she believes she has to do to be 'worthy' of Lal'C's attention. It also explores her interactions with the rest of the Idols, her efforts to fit in and, ultimately, the truth to her forgotten past.

After dealing with swarms of space monsters, and the personal conflicts of the Topless themselves, the empire discovers a threat of a real space monster when the Serpentine Sisters attempt to awaken something they call 'an eternal Topless', which could destroy the space monsters for them and provide them with a way to keep from ever losing their Topless power. This so-called 'Topless' is actually a true space monster, as Lal'C learns when she witnesses its vicious attacks against her comrades and, horrified, asks Dix-Neuf (her Buster Machine) what this creature might be. The fact that the monsters Topless had been battling up to this point were merely first generation alternate Buster Machines, used to protect the human race from true space monsters in earlier generations as a Solar Defense Force, is also revealed. During these events, Nono's potent powers as Buster Machine no. 7 awakens, she and the Topless do battle with the real space monster and is victorious. Nearing the end of the story, they encounter the last of the space monsters carrying a black hole and utilizing it as an energy source to warp from system to system. The empire plans to use Nono's Buster Machine powers and the artificial Buster Machines to destroy the final Space Monster. However, Lal'C and the Fraternity find themselves useless during this time, and one of the Topless is permanently put out of commission when he has finally reached his age. Nono attempts to hold back the monster, but to no avail. Lal'C then brings Jupiter 2 outof orbit and seems to summon it the way she summons Dix-Neuf, causing it to crash directly into the monster- which shows no signs of damage.

The Space Monster warps closer to earth, Nono suddenly departs with the Solar Defence Force, and seemingly vanishes from the system. The empire decides to use Earth as a weapon to destroy the final Space Monster to ensure their survival. Meanwhile, Lal'C for the first time, delves into Nono's past, How she learned to idolize "Nonoriri" and the man who found her in the depths of Space. She and the remainder of the Topless prepare for the Space Monster's arrival and the timely intervention of Nono, who now becomes the mega android DieBuster. However, frustrated with Nono's departure, Lal'C batters "DieBuster" in a fit of rage. Just as she is about to land a killer blow using Douze-Mille's reformed components as a Buster Machine, her Topless powers suddenly expire. "DieBuster" attempts to attack the Space Monster, with no effect. However, the monster vaporizes "DieBuster's" hands. Lal'C unlocks the true cockpit in Dix-Neuf's brain, activating his true form, and coaxes Nono to come out of the disintegrating "DieBuster" and fight with her. With the two girls together once more, and Dix-Neuf's new powers, they defeat the final Space Monster with a Double Inazuma Kick.

However, at the wake of their battle, the Black hole tears open due to the Space Monster's death. Nono and Lal'C share one last moment together as sisters, their hopes, dreams and futures if they had survived, and Nono finally gives Lal'C a piece of her generator, or singularity, in the form of an Origami crane, before using the remnants of the Alternate Buster Machines that comprised "DieBuster" to warp the black hole and herself away from earth. Dix-Neuf saves Lal'C, and brings her back to civilization, where she weeps at the death of Nono.

10 years later, Lal'C becomes an environmentalist and her Topless comrades have moved on from their previous life. She stays on a hill top in the Okinawan coast line, musing about Nono before the city's lights shuts off. She stares in the starry sky, and it is revealed all along that Nono and Lal'C's time line is the setting of the last episode of the first GunBuster OVA, as explicitly said by Lal'C when she first muses about Nono. Its two pilots, Noriko and Kazumi, descend from the remnants of the first ever Buster Machine, and Lal'C vows to tell Noriko about Nono's life and her sacrifice.

Characters
Nono (Seiyū: Yukari Fukui)
 * Hailing from a rural community in the Martian countryside, Nono is a simple and clumsy girl with a big dream: she wants to be a space pilot. And not just any space pilot, but one to rival 'Nonoriri'. Of course, dreaming of being a pilot and actually becoming one are two entirely different things, as she soon finds out upon reaching the city.  Even after landing a somewhat dead-end job as a waitress in one of the city's bars, Nono stubbornly holds on to her ideals, despite the chiding of her boss and the bar's regular patrons.  Her persistence pays off, however, when she encounters a real space pilot in the person of Lal'C Melk Mark, member of the elite Fraternity and current pilot of Buster Machine Dix-Neuf. It is through Lal'C (whom she impulsively dubs her onee-sama, or big sister) that Nono finally finds the means to make her dreams a reality.


 * Possessing a bubbly personality and a near-endless supply of optimism, Nono seems to be a normal, if clumsy, country girl. However, Nono is anything but normal; in fact, she isn't even human, but an android, who cannot quite remember the reason why she was built (though much of her past is revealed later in the series).  She idolizes Lal'C, despite the fact that the latter seems to regard her with mild annoyance, and will do anything to please her.


 * Nono has trace recorded history of Takaya Noriko and Amano Kazumi (The pilots of Buster Machines 1 and 2) in her memory. The very person she Idolizes and wants to become is Takaya Noriko. Due to her damaged memory, Nono cannot remember Noriko's actual name and thus pronounces it Nonoriri. Nono's memory of Amano Kazumi is referenced when she calls Lal'C Onee-sama and when Nono makes origami cranes. The final reference to "Top o Nerae!" from Nono's memory is the catch phrase that she has memorized. "With guts, and effort," spoken in Japanese. Nono sacrifices her life in the last episode by using her generator and the remaining artificial buster machines to seemingly warp a fatal black hole left in the wake of her climactic battle with Lal'C and the final Space Monster, leaving her legacy in a form of a badly done Origami crane.

Lal'C Mellk Mal (Seiyū: Maaya Sakamoto)
 * The current holder of the top kill score among Topless pilots, Lal'C, along with fellow pilots Nicola and Tycho, is part of the so-called 'Idol' group (pilots with exceptionally high kill rates). She is also the current pilot of Buster Machine Dix-Neuf, the oldest buster machine still in operation. Nicknamed 'princess' by her teammates, Lal'C is outwardly cool and self-confident—traits that draw Nono's admiration for her, much to her initial annoyance.  It is Lal'C who helps induct Nono (with some indirect assistance from Nicola) into the Fraternity as an 'auxiliary member', despite the fact that Nono manifests none of the traits associated with being a Topless.


 * While initially bothered by Nono's hero-worship of her, Lal'C gradually gets used to her company, to the point where she can talk about things she would not normally tell anyone. She senses some potential in Nono, and admires the girl's never-give-up attitude a little (though she might act otherwise), but doubts if guts and perseverance alone can make the girl's dreams come true.


 * In the epilogue, she is one of the many inhabitants of earth to welcome Noriko Takaya and Kazumi Amano and presumably passes Nono's legacy and gift to Noriko.

Nicola Vacheron (Seiyū: Mitsuo Iwata)


 * The only male Topless on the 'Idol' team, Nicola is the pilot of Buster Machine Vingt-Sept and, before Lal'C's inclusion into the ranks of the Topless, was considered one of the most powerful Topless of his generation. He is Lal'C's inspiration (in as much as Lal'C is Nono's inspiration), and seems to have a relationship with her, though it is debatable whether it is of a romantic nature or not.  He is interested in Nono and sees potential in her to be a Buster Machine pilot, despite the fact that Nono has never manifested any kind of Topless reaction (something that, according to their minder Casio, may not be possible in artificial beings), and secretly helps Nono join the Fraternity under the premise of being an 'auxiliary' member.


 * Considered 'old' among the current Topless (as he is nearing late adolescence), Nicola is already having a hard time manifesting the Exotic Maneuvers needed to power his machine. As such, he seems to secretly be seeking a way to extend his 'tenure' as a Topless, to the point of joining the Serpentine Twin's inner circle and acting as their watcher over Nono's activities.


 * He ultimately loses his ability to pilot the Buster machine and becomes a lieutenant in the empire. His fate in the final episode is unknown.

Tycho Science (Seiyū: Miyuki Sawashiro)


 * The final member of the 'Idol' team, Tycho is brash, impulsive, and utterly determined (at least in the beginning) to best Lal'C's longstanding kill record, seeing it as a chance to wipe the normally smug look off the face of the teacher's pet(another of Lal'C's nicknames among the members of the Fraternity). She has a low opinion of Topless in general (despite the fact that she's a Topless herself) due to an event in her childhood where—in spite of her powers—she was unable to cure the illness of a close friend, and is annoyed by Nono's constant attempts to prove herself worthy to become a Buster Machine pilot.  Ironically, it is Nono who later helps her change her way of thinking for the better.  While it isn't outwardly implied, the two become friends, though not on the same level as Nono and Lal'C.


 * Initially Tycho pilots the Buster Machine No.66: Soixante-Six, but it is destroyed when (against her initial orders) she uses it to impulsively attack the Jupiter Express (a massive swarm of space monsters that roamed the space between Jupiter and Saturn). After a period of self-doubt, she is able to awaken Buster Machine Quatre-Vingt-Dix, and it remains her machine for the rest of the series.


 * In the epilogue, Tycho becomes an emissary of earth and travels to various systems with the corps. She wasn't present during the homecoming of Noriko and Kazumi.

Casio Takashiro (Seiyū: Takumi Yamazaki)


 * The only adult member of the 'Idol' team, Casio is their guardian, technician, and confidant rolled into one. A former Topless himself (he was a pilot of Dix-Neuf before Lal'C joined the Fraternity), Casio possesses an intimate understanding of the workings of the Buster Machines, as well as the people forced to pilot them.  That is part of why he was one of the first to express his doubts on Nicola's assertion that Nono had the potential to become a pilot.  Despite his initial misgivings, however, he joins Lal'C in welcoming Nono into their 'team'.


 * Despite being a lech and a joker, Casio can be surprisingly serious when the situation merits it. He secretly yearns to pilot a Buster Machine again, but is resigned to the fact that he can only be near them, due to his advanced age.  He is aware of the shady activities of the Serpentine Twins, but not the exact details of their little 'project.' Casio's fate at the end of the series is unknown, but presumably remains an engineer in the empire.

The Serpentine Sisters


 * Two highly mysterious members of Topless, the Serpentine Sisters are the oldest living Topless. They plan to awaken something inside the moon Titan that will give them the secret to eternal Topless powers, and are revealed to actually consume its meat in order to prolong their powers until they can awaken the 'fluctuating gravity well', as they call it. Their true motivation for needing these powers is the fact that without them, they might lose their close connection.

Buster Machines
Unlike the mechs seen in Gunbuster, the Buster Machines in Diebuster appear to be sentient biomechanical mecha built by some unspecified Buster Machine corporation, which are actually later generations of the first two Buster Machines from the first OVA. According to Casio, the oldest functioning Buster Machine, Dix-Neuf, is more than several thousand years old. The process of constructing the Buster Machines seems to be extremely complex, to the point that only fifty percent of the machines built ever “awaken”. This explains why, at the time of Episode 2, only 32 Buster Machines were still in operation, from a total of 90. The mechs all have spherical cockpits which resemble a baseball, and the control mechanisms resemble bicycle and automotive parts such as bike handles, seats, brakes, and so on. The Buster Machine names are derived from the French Vigesimal numeric system.

Listed below are a few of the more prominent Buster Machines featured in the series.

Buster Machine No. 19: Dix-Neuf


 * The oldest Buster Machine still in active service, its name literally means "nineteen" in French. It is piloted by Lal'C. Its appearance resembles a stereotypical Japanese bike gangster Bōsōzoku; sporting a long dark trench coat covering its muscular-looking body with baggy matching "pants". It has a huge red scar running through its chest and abdomen, and an artificial metal left arm. Dix-Neuf has a cruise mode wherein it resembles a huge space rocket. Its wide array of weaponry includes finger-mounted machine guns, the Buster Gator (a hand-held chainsaw/knuckle weapon augmented by the right forearm rockets), Buster Beam, Buster Mite (missiles located in its left forearm), and Burning Wall (micro-missiles stored in the inner layer of its coat) to name a few. When its coat is removed, a huge bronze oni (Japanese demon) face with red eyes and flaming horns is revealed on its back which is capable of offense using eye beams. When detached, its coat can also transform into a large laser cannon. It also has the ability to teleport to where Lal'C summons it to be when the Topless seal on her forehead is removed.


 * While capable of battling opponents without a pilot (due to its accumulative AI), Dix-Neuf's true potential is unleashed when a Topless pilots it: its mobility increases exponentially, its otherwise rigid trench coat is able to flex and move almost as if it weighed little more than a piece of clothing, and it can use weaponry powered by its Topless pilot's Exotic Maneuvers.


 * Dix-Neuf had its Degeneracy generator removed and replaced with a cockpit in the chest. This may have been done to bury the technology to keep humans in the solar system, or simply because of the horn going through its right eye, blocking access to the original cockpit located in its head. In its true form, after Lal'C and Dix-Neuf violently installed a Degeneracy generator from one of the fallen Buster Corps "space monster" into itself, the entire machine turns red, with the heavy overcoat turned into pure energy. The large mouthpiece is removed, exposing a human face.


 * Dix-Neuf saves Lal'C one last time when Nono warps the black hole away from earth, its presumably sealed off with the other buster machines as there are no more threats from Space Monsters.

Buster Machine No. 27: Vingt-Sept


 * The Buster Machine that Nicola pilots, Vingt-Sept is a somewhat gangly-looking machine sporting outstretched wings which can be used as a secondary pair of arms at its shoulders that house a multitude of speaker-like openings on its surface, which likely help magnify the range and effect of the reality-bending Exotic Maneuvers Nicola uses. It has the ability to create reality distortions which it can use to manipulate objects around it and use them as offensive weapons, other than that it has two swords for slicing through the enemy. Designed primarily for quick movement and melee combat, Vingt-Sept is light on ranged attacks, relying instead on remote-detonated 'mines,' as evidenced in the battle against the Jupiter Express. Its name means "twenty-seven" in French.


 * Vingt-Sept was sealed away with the other buster machines in the final episode as there are no more threats of Space Monsters.

Buster Machine No. 42: Quarante-Deux


 * This designation seems to refer to the two separate Buster Machines of the Serpentine Sisters, one of which is orange, and the other pink. These Machines combine together into something resembling a gargoyle's head in Episode 4, and attempt to converse with the 'eternal Topless' (in reality a true Space Monster), which fires on them and destroys them in return. Their offensive capabilities, if any, are not known.

Buster Machine No. 66: Soixante-Six


 * This is Tycho's first Buster Machine. Only having a few seconds of screen time in Episode 3, Soixante-Six is seen to have a sort of energy mace connected to its hand as a primary weapon. This was used to great effect during the first few seconds of the battle. However, Soixante-Six's demise occurred when Tycho's right earring snapped, distracting her for a few fatal seconds and leading to Soixante-Six being rammed by the space monsters.

Buster Machine No. 87: Quatre-Vingt-Sept


 * Gurkha Kuksis's Machine. This machine was only ever seen in the background, and very little is known about it. It appears to be colored silver, with four limbs that look more like booster rockets than legs. They are also positioned like booster rockets at the stern of the main body, and seem to have no flexibility, leading us to believe that this Buster Machine is more like a spaceship than a mecha. Quatre-Vingt-Sept's signature attack is called the Buster Boulder Crush, but no information is given as to the attack's effect other than another Topless forcibly trying to stop Gurkha from using it.

Buster Machine No. 89: Quatre-Vingt-Neuf
 * Lou Seun's Buster Machine, the newest machine besides Quatre-Vingt-Dix. It seems to be modeled on a giant flower, with the petals pointing aft in flight. Its signature attack is the Buster Blossom, wherein its four 'petals' appear to split from the main body and attack. It also has two long, whiplike feelers attached to its head, whose purposes are unknown.

Buster Machine No. 90: Quatre-Vingt-Dix


 * Tycho's final Buster Machine, Quatre-Vingt-Dix is the newest model to be rolled out of the factories in more than a decade. Slim and feminine in appearance (even sporting a pink and white paint job), Quatre-Vingt-Dix seems to be designed as a long-ranged support unit, as most of the attacks it displays in the series seemed to be ranged (as well as affecting wide areas) in nature.  It is famous for its Buster Smash, a tennis-inspired wide-area attack capable of freezing large numbers of opponents instantaneously. Its name means "ninety" in French.


 * Quatre-Vingt-Dix was sealed away with the other buster machines in the final episode as there are no more threats of Space Monsters.

Buster Machine No. 7


 * Though alluded to throughout the series, in the fourth episode, it is revealed that Nono is in fact a buster machine. Hints to this included Nono's Inazuma Kick in the 1st episode, and her connection with Buster Machines highlighted by Dix-Neuf's power up in the 2nd, Quatre-Vingt-Dix awakening in the 3rd, as well as the ominous feeling of the true Space Monster Fraternity mistook as an alien Buster Machine, and the Serpentine Sisters thought was an alien Topless (which it actually is, since Topless are an evolution to bring humanity closer to Space Monsters making them the new 'white cells' for the galaxy.)  Nono herself is formidable, with the ability to warp almost instantaneously using the singularity built into her.  Using three special lenses on the back of her hands and her chest, she can absorb energy blasts.  Upon her legs are eight banks of lasers similar to the ones used on the old Exelion, as well as additional thrusters.  Finally, she can fire off a Buster Beam, or her rendition of a slicing maneuver, where she has the power to cut a moon in half. Not to mention the ability to create multitudes of micro-black holes. However, her greatest ability is to control what is referred to in this series as 'Space Monsters', which are actually the Buster Corps support unit built to protect the solar system from the true Space Monsters.  The greatest show of this is when the entirety of the collective Buster Corps patrolling and encircling the Solar System is assembled, creating the largest Buster Machine combination to date, 'Diebuster'.  It is a gigantic red-colored rendition of Nono, though the outfit bears a close resemblance to the legacy Top Squadron uniforms from Gunbuster.  Assembled, it is comparable in size to Earth. In this form, Nono resides in the large crest upon the machine's forehead, which resembles the insignia of the space fleet from Gunbuster. She dies at the final episode when she uses her Singularity (or Generator) to warp the Black Hole left in her battle with Lal'C's Dix-Neuf and the Final Space Monster.

Space Monsters
Gigantic life-forms of unknown origin that travel the spaceways in massive swarms (termed 'Expresses') composed of tens of thousands of creatures each, space monsters are considered a threat for the sheer amount of damage they can cause to human settlements. Only the Buster Machines seem to have the ability to battle them, but the sheer numbers of some swarms can overwhelm even the best Topless pilot.

Coming in an assortment of shapes and sizes, the space monsters possess natural weaponry on par with the Buster Machines. Some forms can generate blasts of energy, while others spawn smaller versions of themselves that then proceed to impale their opponents. A few forms seem to eschew ranged attacks completely, and primarily use ramming attacks to overwhelm their foes.

It is not known precisely where the space monsters come from, or why they are attacking humanity, but it is generally believed that a 'mother swarm' encircles the Solar System outside of the planet Pluto (which resembles a nebulous cloud of red material when viewed from afar), preventing humanity from travelling further into space.

In fact, the 'space monsters' that the Fraternity have been battling for so long are actually an autonomous and self-evolving defense system left behind by the Imperial Space Navy to guard the solar system in the aftermath of the Galaxy Center Throw mission (The end of Gunbuster 1). The irony of the situation is the fact that, after centuries of auto-evolution, the 'guardians' adapted forms similar to their programmed enemies (the real space monsters from the first Gunbuster OVA) as they were more efficient. Humanity is besieged by their former protectors because of their own evolution. The similarity of Topless' psionic powers resembles the powers of the variable gravity wells, the true space monsters humanity once fought. It is almost as if humanity will one day replace the space monsters that acted like the galaxy's immune system.

There are two forms of Space Monsters. The Space Monsters under the command of Buster Machine No. 7 are Man made and serve as alternative Buster Machine. A real Space Monster is never encountered until episode 4 of "Top o Nerae 2!" The first actual Space Monster was discovered in the process of researching sub-light speed. Space Monsters move from one solar system to another consuming stars and multiplying. In episode 5, a Space monster attaches itself and feeds on a Black Hole (created in Gunbuster 1 by the humans). Once It saw the humanity and the earth as a threat, it was decided that humanity would have to sacrifice the earth to defend themselves. Only with the sacrifice of Nono and the artificial alternative Buster Machines, did they ultimately defeat the final Space monster.

Episodes

 * 1) Please Let Me Call You Big Sister! (お姉さまと呼ばせてください!)
 * 2) Don't call me Big Sis! (お姉さまなんかになりたくない)
 * 3) I hate Topless! (トップレスなんて大嫌い)
 * 4) Resurrection! The Legendary Buster Machine! (復活!! 伝説のバスターマシン!)
 * 5) They who move the Stars (星を動かすもの)
 * 6) The Story of Your Life (あなたの人生の物語)

Style
The art style of the show is drastically different from the 1988 original Gunbuster. Director Kazuya Tsurumaki, scriptwriter Yoji Enokido, producer Hironori Sato, and character designer Yoshiyuki Sadamoto all previously worked together on the anime FLCL. This is reflected in both the artistic style and in thematic elements. They also appear to be set in a similar universe. The Fraternity, mentioned in FLCL, is one of the chief entities in Diebuster.

Regarding the show's influences, Tsurumaki said, “Since I’m directing the show, you know there’s going to be some FLCL-ishness… [We] all have differing opinions on how this new series should go. Sato likes hot-blooded sports shows, while Enokido wants to do a story about an average boy coming to realize his own weaknesses and fighting to make a better life for himself, like in Evangelion and Nadia. What I want to do is combine a bunch of technical sci-fi concepts with an indescribably weird mood.”

Music and theme songs
Many music in Diebuster is recomposed based on the music used in Gunbuster. A famous example would be the 'Buster Machine March' which played in Gunbuster during the Gunbuster's first combat sortie, it plays in episodes 1, 4, and 6 of Diebuster.

The music was composed and conducted by Kōhei Tanaka, the composer of Gunbuster.

Opening Theme
 * "Groovin' Magic", by ROUND TABLE feat. Nino

Ending Theme
 * "Hoshikuzu Namida" (Stardust Tears), by ACKO

Allusions to other anime

 * The name of the flagship Lalacharn featured in episode two is a combination of the names Lalah and Char; a homage to the original Gundam series.
 * Nono's assertion that anything could be achieved through willpower and effort is the same idea that Koichiro "Coach" Ota seems to constantly remind Noriko of.
 * Nono's lightning kick in the first episode is a homage to the lightning kick from the original Gunbuster OVA. Similarly, Dix-Neuf finishes off the attacking space monster with a Buster Beam, named after one of the Gunbuster's attacks.
 * In episode 2, Nicola calls Nono's lightning kick a Rider Kick. The Rider Kick is the traditional finisher of the superhero Kamen Rider of tokusatsu fame, as well as his many successors.
 * In the third episode, the 'planet' Jupiter featured is a ship of similar design to the Exelion.
 * In episode three, while preparing for the arrival of the Jupiter Express, Tycho attacks Nono in an EVO III mechanical suit and demands that she "turn off her marker" (in order to duel). This mirrors a scene between Jung and Amanoh in episode 2 of the original OVA.
 * In episode four, Nono hums a melody from 'Active Heart'; the opening song of the original Gunbuster OVA.
 * In episode four, the music that is played when Lal'C shows Nono the skylarks (named 'Skylark' in the OST) is the recomposition of the song 'Active Heart', sharing the same melody.
 * In the fourth episode, the "Variable Gravity Well" that the Serpentine Twins unearth and revive is revealed to be none other than a cruiser-type Uchuu Kaiju (Space Monster) - the same type that the Gunbuster defeats on its first sortie. In the same episode, there is a scene where Nono is accepted into Dix-Neuf's palm, which mirrors a similar scene in the first OVA (where Kazumi's RX-7 Machine Weapon is accepted into the Gunbuster's palm).
 * In episode 4 there is a sequence in which multiple space monsters impale a buster machine before it can activate its exotic technique. This mirrors a scene in The End of Evangelion in which Asuka's Unit 2 is impaled many times in almost exactly the same manner.
 * In the beginning of episode five, the "Nonoriri" that Nono frequently mentions is revealed to be none other than Noriko Takaya of the original OVA.
 * In episode five, Lal'C is shown kicking her Vespa scooter to the ground in way similar to FLCL's character Haruko in the ending.
 * In episode five, the Space Navy travels beyond Pluto to the Sol system's twelfth 'planet' - the Black Hole, Exelio. It was the black hole created when the Exelion's (the warship that initially carried the Gunbuster) Degenerancy Drive was detonated to destroy the solar system's space monster hive.
 * In episode five, the evacuation of the flagship mirrors a scene in the opening of episode 2 of the original OVA, where Koichiro Ota was supposed to board one of the lifeboats of the damaged Luxion.
 * In episode six, the ending scene parallels the last scene of Gunbuster. This concludes that the events that occur in Diebuster take place around twelve thousand years after, or ten years before the end of, Gunbuster's timeline.
 * In episode six, after Lal'C is given the 'key' to Douze-Mille (~4:10), the image of a 'legendary hidden ruins' strongly resembles, if not actually is, the Eltreum from the original OVA. Furthermore, the key itself strongly resembles the key for Gunbuster 2 passed from Jung to Amano in the original.
 * In episode six, the head crest of Diebuster is the insignia of the space fleet in the original OVA.
 * In episode six, Lal'C dons a uniform resembling the uniform worn by the female pilots of Gunbuster, which was in a knapsack found in Dix-Neuf's original cockpit. Interestingly, the blue knapsack has the insignia of the space fleet of the original OVA.
 * When placing the Degenerancy reactor into Dix-Neuf in episode six, Lal'C's actions mirror Noriko's when she removed Gunbuster's reactor to activate the Black Hole Bomb in the original OVA.
 * At the end of episode six when Nono pulls Lal'C's hand into her body it strongly resembles a scene from another Gainax production, The End of Evangelion when Gendou's hand enters into Rei Ayanami's body via her breast. The fallen Diebuster may have also paid tribute to the fallen Lilith/Rei from End of Evangelion.
 * The "Gunbuster pose" (the "arms-crossed on chest" stance) has been referenced in other GAINAX productions such as Tengen Toppa Gurren Lagann.
 * The smiley-face hairpiece that Nono wears bears a strong resemblance to a similar badge worn on Captain Tylor's trenchcoat in Irresponsible Captain Tylor.