Tonari.

Tonari. summary:

A series of short stories. First Story: Natsume, who is living in a boarding house, goes to the same school as the daughter of the house, Kayo. Though they're friends, they have no romantic feelings, especially since Natsume is a total player and Kayo doesn't understand his attraction for the other girls. But there's a reason he acts like such a playboy; his parents' marriage isn't good, and he doesn't believe anyone would love him for more than a casual encounter.