Emura Akane, Shiina Kuroko, and Hiiragi Himeko are hanging out in the classroom after school when Yoshiko sets her sights on them. The girls, completely unable to read Yoshiko's behavior, get roped into playing with her. They agree to play hide and seek in order to escape Yoshiko, but then...

Nozomi, Masaru, and Mamoru go to buy snacks for their field trip, with 300 yen each as their budget, when Yoshiko tries to initiate them into the finer points of buying field trip snacks. Masaru and Mamoru follow Yoshiko's teachings as they buy their snacks, but Nozomi buys a single expensive snack. Nozomi's field trip will end dark and gloomy... or so they thought!

In order to make the cultural festival that she looked forward to so much a success, Emura volunteers to join the cultural festival committee. Progress on the class attraction is slow, so she and her friends stay overnight at school to get some work done, but then Yoshiko enters the scene. The three girls try to get rid of her, but they get sucked into her game...

Yoshiko goes out for a walk with her dog. But their walk is no simple walk. Yoshiko rides on her dog's back, and eventually they reach the mountains. A race breaks out between Yoshiko and her dog traveling at unprecedented speed and the legendary rider of the peak. Who will be the victor?