Karen Bee, Part Two Episode 2

Araragi turns up at Sengoku’s house, and tries to not get turned on by her lack of clothes and seductive advances at a time when her parents are conveniently out. After he leaves, he meets his sister Karen on the way to Kanbaru’s house, where he realizes that the Fire Sisters are up to something suspicious but decides not to interfere. When he catches Kanbaru completely naked and starts questioning how much of a pervert she is, Kanbaru jumps him and starts taking off Araragi’s clothes, and he promises to never molest Hachikuji again.