Ano Koro to Ima, Kimi ga Koboreru

'Which is more important, me or him?' Miyako, a freelance writer, and Aki, a junior high school teacher, are lovers. One day, however, he suddenly loses contact with Aki, who is on his way to a club training camp. Driven by anxiety, Miyako looks up and sees Aki, a high school student, in front of him. Confused by the unbelievable situation, Miyako decides to have sex with the high school student Aki, hoping to get back to the "Aki of today" as soon as possible. However, nothing changes afterwards, and the "Aki of today" returns home without incident. From that day onwards, a mysterious life with the two Akis begins...?