Kame is an unpopular NEET who only thinks about butts. Kame's childhood friend, the dark-skinned gal Lan Hua, is extremely lonely and comes to Kame's house almost every day to relax and kill time as if it were her own. Kame doesn't see Lan Hua as a member of the opposite sex, but he gets an erection when he sees Lan Hua's butt, and he secretly masturbates, which Lan Hua sees. Unable to resist, Kame buries his face in Lan Hua's butt and ends up having sex with his childhood friend...