Riko is a childhood friend of mine who was in the same class as me. One day, while we were studying for exams together, I touched a girl’s breasts for the first time at Riko’s request. Since then, I couldn’t help but be curious about Riko’s breasts, both at school and after school, and whenever I had free time, I would sneakily touch her breasts. And the two of us discovered that nipples in particular felt good…