My sister is a high school girl who is serious and an honor student in front of her family, but even I, her older brother, think she's super cute! I wanted to know how she spends her time in her room, so I set up a camera in her Kokoro to take some secret footage, and I ended up capturing some incredibly lewd footage that far exceeded my expectations, and was far more than I could have Haruka imagined from her usual serious appearance! She let her guard down because it was her own room! Her sexual preferences were completely exposed! I made an AV out of the shocking footage that I would never show to my parents!