While his parents are away, his childhood friend Mei comes to visit him. They've been friends for ages, neither of them having a boyfriend or girlfriend, but they're in a casual relationship that's more than friends but less than lovers. On a hot summer day, alone at home, they play their usual games and then, without even knowing it, they kiss. Then they have some lovey-dovey creampie sex! During meals, in the bath, and in the morning...