The story centers on 25-year-old theater actor Kana Ashishima and his lover, 30-year-old bus driver Yūki Kawata. The two have enjoyed living together happily in love. One day, Kana awakens to find himself with the body of a child. Kana doesn't know why his body has reverted to a child or how to return to his adult body. The happy couple now find themselves in a fearful situation. Until this moment, the two lovers satisfied one another to their hearts' content, but no matter how they feel now they cannot act on their desires.

Includes the one-shot Between Affinity and Amicability (Tamaisan, Koi to Yuujou, 玉井さん、恋と友情), an extra story for The First Thing I Do in the Morning Is. Originally published in Joshi BL.