I seriously thought big sister was going to get a fist to the face. Kaoru has better self-control than I would have in her place.
Btw I learned a new sound effect. The sound of a Cupid arrow that strikes your heart is "zudo" and, if a LOT of Cupid arrows strike your heart at the same time, it's "zudododododo..." with an extra "do" for each arrow. Good to know, I guess.