COGM-052 I can tolerate my sister being a nudist, but it's really troublesome that she masturbates anywhere and anytime.

※A new label for Koguma has arrived! Its name is Organic INRAN! The theme is 'What if there's such a perverted kid in your daily life!' My sister is a nudist. That's still tolerable. It's a story you hear quite often. But she's also addicted to masturbation. No joke. She really seems to masturbate on a daily basis, and might actually die if she doesn't touch her pussy for a while. But I'm a college student. My sister works and earns the living expenses, so I can't say anything. Although I know I should say something as her brother, there's also a part of me that gets excited watching her, so I can't bring myself to say it. If she acknowledges my warning with an 'Ah, understood,' that would be sad in its own way. While I was in turmoil like this, my sister asked me to help her masturbate. What do I do? I'm practically a virgin!