Ji-won is an erotic writer, but she has not had sex yet, so she cannot write realistically. Eun-sik and Seong-gook compete for their first sex under the pretext that Ji-won is a virgin for her work, and Seong-gook's plan goes up in smoke when his wife Hyeon-hee returns home. On the other hand, Hyeon-hee is curious about Eun-sik and approaches him because his previous job is adult learning and mastering. In this situation, will Ji-won be able to finish her first sex safely and write a huge masterpiece?

Soo-yeong and Hae-soo are college friends stuck in a love tangle: Soo-yeong likes Che-moo, but Che-moo likes Hae-soo. Meanwhile, Hae-soo likes Dae-in, but Dae-in likes Soo-yeong. Despite the mixed-up feelings, they end up in mismatched marriages. Later, Hae-soo wants to have a baby and tries to get closer to her husband, Dae-in. But Dae-in knows he can’t have children, so he secretly makes a surprising proposal to Soo-yeong’s husband, Che-moo.