Tokyo is on edge due to a rash of recent killings targeting Butei - armed mercenaries that perform odd jobs and capture criminals. So when Kinji, a student at a local Butei high school, heads to class one day and discovers a bomb has been rigged to his bike, he’s certain he’ll be the next victim. That is, until Kinji’s elite classmate Aria saves his life, inadvertently triggering his superhuman ability that flares when he’s sexually aroused! Though Kinji would rather slack off at school and be left alone, Aria is now determined to make the teenager her slave, fetching her food and partnering with her on missions - including one very important to the girl. And nothing will stand in her way... not even Kinji's possessive childhood friend!