Chisato and Riku first met when she moved next door ten years ago. Even as college students, they're still neighbors after her mom suggests they get adjacent apartments since "it'll be safer." One day, Chisato casually mentions she wouldn't mind having a boyfriend. Riku's reaction of "Why not me!? I've had a crush on you forever!" totally catches her off guard. Can someone who's been the boy next-door for most of her life become something more...!?