Minato soon learns that he is an 'Ashikabi', humans with special genes that allows them to partner with 'Sekirei'. The Sekirei are super-powered beings created by the mysterious MBI corporation. Made up of cute girls, buxom women, and bishōnen, the Sekirei fight in a dangerous and sometimes deadly competition called the 'Sekirei Plan'.
With the entire city of Tokyo as the battlefield, the Sekirei seek out those humans who are destined to become their Ashikabi partner. 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.