Sekirei

Sekirei (セキレイ) is a Japanese manga series by Sakurako Gokurakuin. Originally starting serialization in the seinen magazine Young Gangan published by Square Enix in June 2005, Sekirei is a manga aimed at young men. An anime adaptation produced by Seven Arcs and directed by Keizō Kusakawa was aired in Japan between July and September 2008. The central character of the series is Minato Sahashi, a ronin who failed college examinations twice. His life changes, however, when he meets a girl named Musubi.

Plot
In Tokyo in the year 2020, Minato Sahashi has failed the college entrance exam twice, is awkward around women, and he's unemployed. He could never stand up to his mother or little sister growing up, a trend that continues to this day. In reality, Minato is extremely intelligent, yet his inability to cope under pressure results in his constant failure and he has been branded an idiot and loser by many as a result. One day, Minato meets a girl named Musubi, who literally falls from the sky. Minato soon learns that she is one of the "Sekirei" and he is her "Ashikabi", a human with special genes that allows them to "wing" (form a contract with) a Sekirei. This binds the Sekirei to him and allows them to use their full power in the elimination battle with other Sekirei. Made up of cute girls, buxom women, and bishōnen, the Sekirei fight in a dangerous and sometimes deadly competition known as "The Game" or the "Sekirei Plan" organized by Hiroto Minaka, the chairman and founder of the mysterious and powerful MBI Corporation. Minato soon learns that being the partner of a beautiful girl is not all fun and games, especially when he discovers that an Ashikabi can have more than one Sekirei partner—and that's where the real trouble starts.

Sekirei
The Sekirei are extraterrestrial superpowered beings with a genetic code similar to humans. The Sekirei spaceship crashed on Earth in 1999 and was found by students Hiroto Minaka (future MBI chairman) and Sahashi Takami (future MBI head researcher and Minato's mother). Onboard, the pair had found 108 life-forms, described as "One pillar and 107 baby birds". The adult and the eight embryos are also known as the "Single Numbers". It is hinted that unwinged Single Numbers are equal or even more powerful than their winged counterparts. All of the Sekirei had undergone adjustments for the "Sekirei Plan", especially the Single Numbers (some of their adjustments were mischievous). The adjustments had been undergone not only for making Sekirei stronger, but also for controlling and stabilizing their power.
 * The first of them (a pillar, shown as #00, possibly later renumbered and known as #01) was an adult.
 * Eight (later known as #02-06, 08-09, eighth of them is #01 or unnamed #07) were embryos.
 * 99 others (later known as #10-108) were fertilized eggs.

Also, 8 mysterious artifacts called Jinki (神器), numbered from #1 to #8 , were also found on the Sekirei spaceship. If all eight of them are gathered, it is possible that they can be used to terminate all of the Sekirei if the weilder desires. Multiple Sekirei that are under the same Ashikabi can also merge their techniques in order to create more powerful techniques. This puts most Ashikabi at a disadvantage, as only a few Ashikabi posses more than one Sekirei.

Ashikabi
Ashikabi (葦牙) are humans with unique genes that enable them to empower the Sekirei destined to serve them. Through an exchange of saliva between a Sekirei and its Ashikabi (usually done through a kiss), a Sekirei without wings can become a "winged" Sekirei. Unlike Sekirei, who are mostly buxom women or handsome young men, Ashikabi can be quite innocuous as they can appear in any gender, age, and even status. In the series, the power of an Ashikabi can be determined not only by the number of the Sekirei he or she has in his or her disposal, but by the bond between them. Four Ashikabi in particular, including Minato, are considered the most powerful ones having titles based on their names followed by what part of the city they rule over. If an Ashikabi dies, all of the Sekirei winged by him or her will also perish.

Game
The third match of Stage Three of the Game has ended in the manga currently, while season 1 of the anime ended in the middle of the Second Stage.
 * First Stage: The Sekirei are freed and they must find their Ashikabi for winging. This stage ended when 90% of the Sekirei had been winged.
 * Second Stage: Tokyo becomes a closed city and no Sekirei or Ashikabi can leave. The Ashikabi must then wing the remaining unwinged Sekirei.
 * Third Stage: The series of matches between Ashikabi with the grand prize being one of the Jinki. Three teams (an Ashikabi and up to three Sekirei) participate in the first and third (current) match. Five pairs (an Ashikabi and one Sekirei) participate in the second match.

Manga
Sekirei began as a manga series which started serialization in the seinen manga magazine Young Gangan in June 2005, published by Square Enix. As of December 25, 2009, nine bound volumes have been released.

Drama CD
A drama CD entitled Sekirei Original Drama CD was released on July 25, 2007 by Frontier Works.

Anime
The first 12-episode anime series adaptation produced by the animation studio Seven Arcs and directed by Keizō Kusakawa aired in Japan between July 2 and September 17, 2008. The anime is licensed by Aniplex in Japan. The first season is mostly faithful to the overall story structure of the manga series, covering roughly the first fifty chapters of the series. The opening theme is "Sekirei" (セキレイ) and main ending theme is "Dear sweet heart", both songs performed by Saori Hayami (#88 Musubi), Marina Inoue (#9 Tsukiumi), Kana Hanazawa (#108 Kusano) and Aya Endo (#2 Matsu). The ending theme used in episode eleven is "Kimi o Omou Toki" (きみを想うとき) by Hayami.

Six DVDs of the first season were released between October 22, 2008 and March 25, 2009. DVD volume six was supplemented with an original video animation episode, "The First Errand" (初メテノオツカイ), featuring Kusano participating in the shopping race with Musubi and Tsukiumi. A Blu-ray box set of the first season will be released on June 30, 2010 with three Blu-ray discs and one additional CD. At Anime USA 2009, Funimation Entertainment announced that the anime's first season was licensed and will be released in 2010. A second season entitled Sekirei: Pure Engagement began airing on July 4, 2010 on Tokyo MX and on July 6, 2010 on some other Japanese networks. The first episode of Sekirei: Pure Engagement was pre-aired on June 13, 2010.

Video game
A video game for PlayStation 2 entitled Sekirei ~Gifts from the Future~ (セキレイ ～未来からのおくりもの～) was released on October 29, 2009 by Alchemist.