Eripiyo is initially a woman leading a normal life until it is turned upside down after watching a performance of the minor idol group ChamJam, which leads her to becoming obsessed with one of its members, Maina Ichii. Despite Eripiyo's enthusiasm towards her, Maina is consistently the least popular member of the group, leaving Eripiyo to take it upon herself to buy a lot of Maina's merchandise, which mainly involves singles.
Stage version of "Umimachi diary", a story of a heartrending yet gentle family bond woven by sisters living in a town with a view of the sea; a fusion of theater and music. The eldest daughter, Sachi, is a steady person, the second daughter, Yoshino, who loves alcohol and is vulnerable to younger men, and the third daughter, Chika, who always goes at her own pace. The news of her father's death reaches the three people who lived in the Kamakura house left by her grandmother. And she will welcome a “half-sister” left by her father, who had been separated from her when she was young.