Youji and Otuna had a peaceful married life. However, one day, due to her wife Otuna’s curiosity, her husband Youji was transformed into a child because of the medicine she made! Youji spends his days as a child through trial and error in order to return to his original form, but success is far away. With the understanding of those around him, just when he’s getting used to his life as a child, Otona’s father finally finds out about this situation…?