The Sekirei Plan (鶺鴒計画, Sekirei Keikaku), previously called the S-Plan, was originally an operation enacted to protect the "sleeping birds" (sleeping Sekirei), keeping them safe from the hostile forces attacking Kamikura Island. However, it was later turned into a dangerous and sometimes deadly competition developed and overseen by Minaka Hiroto, the CEO of MBI. The Plan has concluded in the manga, and its future was left uncertain after the conclusion of the second season of the anime. It is hinted by Matsu that there will be 6 stages in total.
Teito becomes a closed city, only allowing non-participant humans to evacuate the city through highly guarded security checkpoints. No Sekirei and Ashikabi can leave, and those that attempt to are quickly hunted down by the Disciplinary Squad, who have been granted permission to use lethal force against both Ashikabi and Sekirei. As demonstrated by Benitsubasa and Haihane's revenge mission against Minato's party (anime only), and Karasuba's killing sprees, they are also allowed to fight and kill freely, in addition to when ordered to do so. Fights in both the First and Second Stage are typically limited to small skirmishes, often between unwinged Sekirei preventing themselves from being taken by Sekirei of Ashikabi who forcibly wing Sekirei, such as Izumi Higa and Hayato Mikogami. This is best demonstrated by the hunts conducted by one or both of the aforementioned Ashikabi to gain Sekirei such as Homura, Kusano, and Shiina, and eliminate Sekirei such as Kuno and Natsu. The Ashikabi must wing the remaining 10% unwinged Sekirei.
A series of matches between Ashikabi. The prize for the winner of the match is one of the Jinki. The purpose of this stage seems to be to test the bond between the Ashikabis and their Sekirei. The mandatory nature of fighting within this stage to remain alive (Ashikabi) and active (Sekirei), further emphasizes the life-threatening, war-like reality of Minaka's "game", and increases the danger experienced from that of the first two stages.
Three teams (Ashikabi and up to three Sekirei) participate. The rules are that the first Ashikabi who retrieves the Jinki from its location on the battlefield is the winner.
Five pairs (Ashikabi and one Sekirei) participate in the second match. The rules are that the first Ashikabi who retrieves the Jinki from its location on the battlefield is the winner.
When the participants are revealed, Matsu surmises that Minaka gathered his greatest threats (Minato of the North, and Higa of the East) to be eliminated by the Disciplinary Squad under the guise of the games of the Sekirei Plan.
For the 4th match all Ashikabi are intended to participate even so Minaka mentioned that attendance would be optional. The prize would be the remaining Jinki which would equal chances of success in the later stages. The location this time is on board the "The Minaka", a luxury cruise ship. On board, a "Treasure hunting battle royal" game is to be held, the goal is to retrieve the remaining 3 Jinki hidden on board. The moment all three are found and are in the hands of Ashikabi the fourth match will end. It doesn't matter whether they end up with three different Ashikabi, or if they fall all into one Ashikabi's hands. In the case that all Jinki aren't discovered within a designated time limit, the last three Ashikabi who remain alive with Sekirei unterminated would each receive one of the three Jinki. Once all Jinki were in the hands of Ashikabi the 4th match ended, a countdown began and all Sekirei with an Ashikabi on the cruiser without a Jinki were terminated.
Participants known by name:
- Sahashi Minato
- Sahashi Yukari
- Sanada Nishi (retrieved 1 Jinki/co-winner)
- Seo Kaoru (retrieved 1 Jinki/co-winner)
- Oosumi Orihiko (retrieved 1 Jinki/co-winner)
- Yashiro Itsuki
- several more unnamed Ashikabi
Before the Match even started, 5 Ashikabi retreated frightened by the powerful participants. The remaining unnamed Ashikabi were bribed by Higa Izumi to take down Sahashi Minato, in return they would receive aid to leave the Sekirei Plan. In this match Minato, Sanada, and Seo formed an alliance to carry out a special plan developed by Matsu.
Fourth stage (Kamikura Island)
The remaining Ashikabis from the Third Stage and all of their Sekirei are gathered up by MBI and transported to Kamikura Island, which has somehow moved itself to the bay at the capital. The Ashikabis immediately begin suffering effects similar to radiation poisoning due to the composition of the island (Sekirei are protected by their Sekirei Cores and normal humans are unaffected).
Minaka explains that all of the Ashikabis will die (and therefore so will their Sekirei) unless the 8 Jinki are taken to 8 specific points on the island and placed in special correspondingly-numbered receptacles by an Ashikabi; and there are only 5 minutes to accomplish this. This presents a problem because Minato possesses two Jinki, but their receptacles are on opposite sides of the island; there's no way he can get to both in 5 minutes. Minaka reveals that he is also an Ashikabi, and therefore can take one of them if Minato will agree to split his team. Faced with no alternative, Minato agrees. Musubi, Tsukiumi, and Matsu go with Minaka; Homura, Kazehana and Kusano remain with Minato.
As soon as the Jinki are placed in their receptacles and activated, impassable walls of light surround all of the sites by pairs; thereby creating four arenas occupied by two Ashikabis and their respective Sekirei. Minaka announces that the next challenge is for each pairing to fight to the finish; and if there is not a clear winner within one hour, both Ashikabis and their Sekirei will be terminated.
- Sanada vs. Mikogami (victor)
- Minato (split squad, Minato leading-victor) vs. Higa
- Minato (split squad, Matsu leading due to Minaka choosing to flee from the area-victor) vs. Seo
- Oosumi vs. Natsuo (victor)
Fifth/Final Stage (Kouten)
The last surviving Ashikabi and Sekirei battle Sekirei #01 on the Kouten for the final match.
- Minato Sahashi (Ashikabi) and Musubi (Sekirei representative from his group-victors) vs. Miya
Anime and Manga differences
- In the Anime Tsukiumi's winging instead of Matsu's triggered the second stage.
- In the Anime the third stage has not started yet
- Sekirei Manga chapter 34
- Sekirei Manga chapter 18
- Sekirei Manga chapter 74
- Sekirei Manga chapter 75
- Sekirei Manga chapter 78
- Sekirei Manga chapter 79
- Sekirei Manga chapter 80
- Sekirei Manga chapter 84
- Sekirei Manga chapter 86
- Sekirei Manga chapter 94
- Sekirei Manga chapter 93
- Sekirei Manga chapter 117
- Sekirei Manga chapter 119
- Sekirei Manga chapter 120
- Sekirei Manga chapter 131
- Sekirei Manga chapter 118
- Sekirei anime season 1 episode 07