After Mami finds out she's in danger of failing a course, her mother enlists a private tutor to help her study. Since Mami is busy studying, Rika takes over Mami's part-time job at a restaurant. Since social skills aren't Rika's strong point, she struggles with the job. One day, Mami's private tutor comes to the restaurant, and Rika overhears him talking about how he's trying to sleep with Mami, and she gets extremely angry. After that, Mami finally realizes how kind Rika is, and gives Rika the ticket to the amusement park. Noboru had brought them to Rika's house on her birthday. Clutching the ticket, Rika runs towards the amusement park. Little by little, Rika's surroundings are somehow changing...