Kyoichi Kanzaki is a high school student living in Tokyo with his parents and his older sister Sayaka. He is the central protagonist of the story, an ordinary young man who, in the opening episode, begins to see his childhood friend Chiharu Nitta in a new light and realizes his feelings for her have deepened beyond mere friendship. Kyoichi is inherently kind-hearted, caring, and deeply thoughtful. Although he often appears quiet and reserved, his restraint comes not from detachment but from a genuine fear of emotional vulnerability and getting hurt. Beneath that guarded exterior, he is passionate and sensitive, and he habitually handles situations with a level of maturity and consideration that sets him apart. His introspective personality makes him keenly observant of the people around him, even when he cannot easily voice his own emotions.

His role in the narrative is to anchor the ensemble of friends as they each navigate the joys and heartaches of first love. Kyoichi spends much of his time alongside his close companions Yoshihiko Kenjo and Makoto Kurumizawa, and the group’s interwoven romantic experiences form the backbone of the series. His relationship with Chiharu is central to his journey. She is a dedicated and ambitious track athlete, and their bond, forged over many years, slowly transforms into romance. However, that relationship is not without strain. A significant period of turbulence arises when Kyoichi becomes entangled with another girl, Shoko Sayama, which sends his connection with Chiharu to its lowest point. Later, during a trip to Hokkaido, he works on sketches alongside a girl named Chiharu Reicha, an experience that allows him to reflect through art.

Kyoichi possesses a notable artistic inclination. While Chiharu excels in sports, his strengths lie in creative pursuits such as drawing, painting, and sketching. This ability gives him a quiet outlet for his feelings and a way to perceive and capture the world around him when words are difficult. Throughout the series, Kyoichi undergoes gradual personal growth. He moves from a hesitant adolescent who keeps his heart guarded to someone who begins to take tentative but sincere steps toward expressing his true emotions, ultimately learning to embrace the vulnerability that accompanies love and self-discovery.