Kurogane Hiroto attends high school, where he ranks first academically but is literally the worst at physical activity. Born with a weak constitution, he lacks endurance, speed, and strength, yet Hiroto desires nothing more than to become a hero. Fate teases him by granting him phenomenal eyesight, which allows him to see far better than anyone else in sports, but his body cannot react to any of it. He learns from his friend Shiratori, who wants to recruit him for the Kendo team, about a rumor concerning a ghost named Tojo Sayuri, who wields a katana and haunts an ally in the city. Half curious, Hiroto goes there only to discover that the ghost is real and that Tojo Sayuri has been searching for a successor to her Sakura sword style for 150 years. Sayuri chooses him as the successor after he manages to dodge her attack and forces him to learn the Sakura style. Even with the help of the ancient swordsman ghost, Hiroto must overcome his poor motor skills in order to become the hero he always wanted to be.