On the way back from the summer festival, she, her boyfriend, and his male friend decided to continue drinking at their place. As they got drunk and the conversation escalated, they started joking about whether she was wearing a bra under her yukata or if she had any underwear under her traditional Japanese attire. Driven by alcohol, the crude jokes flew back and forth. Due to a scheme by the male friend, the boyfriend passed out drunk and fell asleep, leaving just the girl and the male friend awake. The unrestrained revelry after the festival began...
