Kei Kusanagi isn't your typical 15-year-old high school student. He's actually an 18 year old with a rare disorder that puts him into what he calls, a 'standstill'. When he was younger, this disorder left him in a deep coma which stunted his growth for the next three years! Mizuho Kazami isn't your typical teacher either. She's actually an alien sent by a secret organization, Kei must... marry the alien?! Homework, dating, and a gorgeous wife - going to school has never been quite this fun!