Ryûichi is having exams, Yôko Morinomiya insisted him to concentrate only on his studies by leaving Kotarô and his club activities to Keigo Saikawa. A special Cinderella act is played by the cast.
Ryûichi is invited by his friends for a movie and he had to leave Kotarô with Keigo Saikawa. On Christmas day, Ryûichi is planning to surprise Kotarô as Santa.
After losing both his parents in a plane crash, teenager Ryûichi Kashima must adjust his life as a guardian of his younger brother Kotarô. They are approached by Yôko Morinomiya, the chairman of an elite school.
The entire babysitters club and parents go to the beach, Inomata is also invited. Taka messes with a most precious thing of Hayato Kamitani, Ryûichi and Hayato Kamitani have a talk about the sibling struggles.
Ryûichi is now in high school, he goes on making a poster to invite new members to the babysitters club. He catches fever the next day and Kotarô is trying hard to help his brother.
After getting a mysterious love letter from his locker, Ryûichi is feeling anxious along with Maria Inomata and Yuki. Taka invites Kotarô to go to the festival with him.
Ryûichi is now in high school, he made a poster to invite new members to the babysitters club. He catches fever the next day and Kotarô is trying hard to help his brother.