071MXGS-1221 Unable to resist the temptation of my suddenly acquired cute stepsister due to my parents’ remarriage… Shiraki Kan’na

A female college student Kanna whose mother remarried and suddenly got a brother-in-law. It’s been about a week since she’s been living with her, but in a situation where she hasn’t had a chance to talk to her, she has taken a certain action on her own. What is that behavior? She looked serious and quiet, but she was actually…