The slightly dominant Ken and the submissive Riko were a well-matched couple, their kinks aligning perfectly. One day, they planned a four-person hot pot party to introduce Riko's friend Sora to a guy, inviting Ken's friend along. However, at the last minute, Ken's friend couldn't make it, leaving them to have the party with just the three of them. Sora, tasked with buying alcohol, accidentally witnesses Ken and Riko having sex. Ken is embarrassed to be caught, while Riko remains oblivious. At the hot pot party, Riko gets drunk and falls asleep early. Taking advantage of the situation, the mischievous Sora starts teasing Ken's nipples...