The film will revolve around a mystery that happens on the day of the "Justice Day" festival that celebrates Sternbild's legendary goddess.

Moe Sato is a young lady who finds a cat and starts taking care of him. Named Poyo due to his round shape, he quickly becomes a dear member of the Sato family. (Source: ANN)

Nan Harding is the new student at Mr. and Mrs. Bhaer's school. Everyone thinks that she is a pain in the head, but not Mrs. Jo. Together with the other kids, they all embark on their personal adventures and misfortunes while learning in school.

Constantly outperformed by the girls' club, the boys' soft tennis club faces disbandment due to their poor skills and lack of positive results in matches. In desperate need of members, Toma Shinjou is looking to recruit capable players, but he fails to scout anyone. Enter Maki Katsuragi, a new transfer student who demonstrates great reflexes when he catches a stray cat in his classroom, instantly capturing Toma's attention. With his interest piqued, Toma ambitiously asks Maki to join the boys' team but is quickly rejected, as Maki doesn't wish to join any clubs. Toma refuses to back down and ends up persuading Maki—only under the condition that Toma will pay him for his participation and cover other club expenses. As Maki joins the team, his incredible form and quick learning allow him to immediately outshine the rest of the team. Although this gives rise to conflict among the boys, Maki challenges and pushes his fellow team members to not only keep up with his seemingly natural talent, but also drive them to devote themselves to the game they once neglected. This story focuses on the potential of the boys' soft tennis club and their discovery of their own capability, while also enduring personal hardships and dealing with the darker side of growing up in middle school. [Written by MAL Rewrite]