Karen Bee, Part One Episode 1

Araragi finds himself chained up in Oshino’s old hideout by Senjougahara, having been kidnapped by her. The scene then shifts to a hot summer’s day, where he ponders on what to do with his unstable vampirism and whether he should tell his two sisters, Karen and Tsukihi about oddities. Deciding to meet up with Sengoku, he heads of to her house but spots Hachikuji Mayoi and stops to chat (molest) to her.