Saku Natsusawa is the eldest son of the Natsusawa family and a second-year student at Chidori High School, where he shares a class with Rintaro Tsumugi. Known for his calm demeanor and intellect, he often keeps his emotions hidden behind long bangs, giving off a cool and slightly unapproachable aura. Despite attending a "bottom-ranking" school, his academic prowess is outstanding, often surprising those who underestimate his abilities. Kind but shy, Saku struggles with direct communication, yet his caring actions and subtle support reveal a gentle heart beneath his stoic exterior. His quiet strength and earnest nature draw friends and classmates to him, even as he grapples with past regrets and hopes for closer bonds in the future.