A man declared the start of the Sekirei Plan from atop a tower. From there, he released 108 Sekirei, each of whom carries great power within them, onto the world of men. There they searched for those who would be their masters, known as Ashikabi. The main character, Sahashi Minato, meets 4 Sekirei (Musubi, Tsukiumi, Matsu, and Kusano) and becomes their Ashikabi. Thus, is he drawn unwillingly into this game, known as the Sekirei Plan, in which Sekirei battle Sekirei until there is only one left. Minato and his Sekirei, in assisting another Ashikabi to escape the city together with his Sekirei, were involved in a major battle against the M.B.I.'s "Disciplinary Squad". Following their victory, the group enjoys a few days of well-earned peace. However, the Sekirei Plan is now moving into its next phase...

Source: AnimeNFO