Kokoro and Kotaro are not good at math and have to take a follow-up exam. Kunihiko Koda (TAKAHIRO), a mathematics teacher, responds to Kotaro, who says "I wonder if there is something I can do suddenly", saying, "There is no such thing. Unless it happens even with Miracle Masmatics." It seems to be an urban legend that has been handed down at this high school, and one student said that he "suddenly became able to do math." I couldn't help but be worried about Miracle Masmatics, but I couldn't concentrate on studying after school, so I went to the health room for some reason. There, he meets Keiko Uchiji (Mitsu Dan), a teacher in the infirmary who knows the secrets of Miracle Masmatics, and asks him to teach him about the "math muscle" that exists in the human body ...