Tập 1: Gia đình Iokawa và Amino đi biển cùng khách mời đặc biệt Shouko, dẫn đến những sự kiện hoán đổi tuổi bất ngờ.

1

At the Iokawa household Karada makes breakfast as well as bentos for the trip she and her older brother are taking to the beach. They meet up with the Amino siblings Tetsumasa and Touko at the station. They are surprised to see the Iokowa siblings bringing along a special guest to the beach named Nogami Shouko. Shouko remains distant during the train ride. Shouko planned on coming back to Japan to start over, and meeting Iokawa Hiro again was outside of her plans. At the beach it is revealed that Karada is going to enter middle school division soon despite her small size. Tetsumasa also has a crush on her. It is revealed to that Nogami Shouko knew Hiro while he was in America, and Touko supposes Shouko used to date Hiro at one time. Karada notices something is wrong, and asks Shouko only to be told she will be told when she is older. Hiro also reveals his sister doesn't like being treated like a child. That evening they go shopping for souvenirs. Hiro buys his little sister Karada a set of white bows. Karada shows the bows off to Shouko who says the bows fit her because they're childish. Karada runs off while Tetsumasa chases after her. Hiro comes out just in time to see Karada run off. After getting back from the train station Hiro tells Karada he needs to talk to Shouko and they head to the bridge nearby. Karada feels she is being treated like a child again. Shouko complains about how she never got to cook for Hiro while she was his girlfriend, and didn't know his favorite food. She also accuses him of leaving him for that girl, and asks why he never told her he had a little sister. She slaps him across the face when he asks her if she still loves him before running off. Shouko and Karada meet beside the wishing stone and under the moonlight the two find themselves switching ages.