After witnessing his sister’s suicide, Kakeru Satsuki lives the remainder of his childhood in an orphanage, where he meets a young girl named Yuka Minase, who becomes his first friend. Yuka helps Kakeru open up to the world again, and they attend high school at Rainbow High together along with two new friends, the slightly perverted Tadashi Teruya and the hot-headed Kaori Natsuki, who keeps Tadashi under control...