Mishima Haruki and Honda Towa are new students at Aokisora High School and best friends. At a convenience store near their high school, Mishima runs into his classmate Mashiki Miharu, a girl he's recognized since he was little.

When Honda spots Miharu having a friendly conversation with their classmate Sanagi Nasa in the waiting room of a hospital, he decides to investigate Sanagi's identity and his relationship with Miharu for the sake of his best friend Mishima.

After participating in the three-legged race with Mami, Honda believes they've grown closer. However, things don't go well when he asks her out on a date.

Summer vacation is over, and the Aozora Cultural Festival is approaching. After things went well with Mami at the fireworks display, Honda is delighted to be spending more time with her preparing for the festival.