Saku Fujigaya faints and misplaces her handbag in a busy train due to her anemia. As soon as she regains consciousness in the hospital, she finds her bag with belongings and a scribbled note that reveals the identity and phone number of the kind stranger who rescued her. Unfortunately, Saku fails to contact them despite trying multiple times. At one point, Saku regarded herself as a background character, barely significant in the eyes of society. But the kind stranger who helped her changed her perspective and instilled new hope in her. She decides to be the change she wants to see and pledges to assist anyone in need. This aspiration stays with her even in high school. On her first day, somebody calls out her name, the same name as the person who saved her. But upon closer inspection, they're looking for another Sakura.