Yasuomi Ohno (Ryo Narita), a single cram school instructor who is not good at communicating with others, is immersed in his favorite world of mathematics. Although he is not dissatisfied with his current life, he is also worried about whether he will always be alone. He also wants to marry normally, but he doesn't know what "normal" means. Even when dating a girl, he feels that there is an atmosphere that is out of focus, but he doesn't know what to do. The student Kasumi (Kaya Kiyohara) is the only one who points out that Ohno is "unusual". So, Ohno asks Kasumi: How can I become "normal"? What is normal?