"Will you stay over at my house starting today?" Riku Kuromine, a second-year high school student, became despondent after being rejected by his childhood friend. He happens to enter a convenience store and saves a clerk who was being attacked by a robber. The clerk turns out to be Ayana Hoshimiya, the most popular and beautiful gal in school. As a result of this incident, Ayana asks Riku to protect her from a stalker and they start living together under the guise of him protecting her as she lives alone.
