Taira Kei has had a talent for contemporary dance since he was young and went to study in Germany to join a dance company in his teens. He has won several international competitions and was referred to as a “prodigy”. However, he encountered a setback in the middle and got frustrated. He returned to Tokyo and takes part-time work while he tries to re-capture his dream. Nishihara Yui is a chemistry teacher in her 30s, working at a prestigious high school. Even while continuing a love affair with a married colleague, she was still lonely until she meets Kei and gets swallowed in passion.
When Shiho Nishina got worried about her sex life with her husband, her husband proposed to her, "Why don't we go to a couple exchange party?" At first Shiho strongly turned down the idea, but eventually, she gave in because her husband was very persuasive. "We're just going to observe, okay?" Shiho said as she reluctantly agreed to it. Meanwhile, a former diplomat Mr. Kubozuka ran a couple exchange club, "Aquarium," with his wife in their house. At first, Shiho was being very cautious, but gradually, she got attracted to Mr. and Mrs. Kubozuka's charm and finally agreed to exchange couples with them. It seemed that their sex problem had disappeard and they had found happiness, but as it turned out, that was just the beginning of their nightmare...
Nitta Masaki is about to start work as a music teacher at a high school. The high school has experienced turbulence due to the missing person case of the prior music teacher. On the night before Nitta Masaki's first day of work, he visits the music classroom and plays the piano. There, he meets student Izumi Sae. She is his student in homeroom class. Through the missing person case, Nitta Masaki and Izumi Sae soon get closer to each other. Nitta Masaki doesn’t want to admit that his feelings for her has turned into love. Meanwhile, Izumi Sae has no doubt that her feelings for him is love. They then part ways. 5 years later, Nitta Masaki & Izumi Sae meet again. There doesn't seem to be any obstacles in front of them to prevent their love, except for one thing. That is Nitta Masaki is a married man, who has a wife.
This is a love story about Ogawa Manami, a high school teacher who grew up in a strict family, and Kaworu, a host who is not good at reading and writing, as they search for love despite the obstacles they face. Manami is being pressured to marry a man she met through her father's introduction, and the high school where she works is also facing a crisis of class collapse. She spends her days lamenting, "I want to run away from this place." One day, she receives a call saying that a student has been deceived by an unscrupulous host, and she rushes to the store to bring the female student back, where she meets Kaworu. Kaworu has to sign a promissory note promising not to contact the student in the future, and Manami finds out about the problem that he had kept secret from anyone until then. In the play, the two gradually become closer through Manami's secret "private lessons," in which she teaches Kaworu about language and society.
