Nishina Tesura wa Suirishinai  

Tesura Nishina does not reason, ニ科てすらは推理しない

The narrative commences by depicting an image of a female standing on a bridge rail. However, it then flashes back several days prior to that moment when a woman aboard a train accused Shunta Momochi, a salaryman, of molesting her. Another girl named Tesura Nishina intervened and resolved the issue before the two disembarked from the train. Despite his initial intentions to simply befriend a high school student, Tesura's "irrational" behavior and Shunta's desire for friendship with a teenager will lead them on an exploration of what Tesura refers to as "meaningless theories," or her term for the enigmas of everyday life.