TV-Series
Description
Shuichi Kuze, a renowned violinist, attended Otobane Academy alongside friends Yuu Himura, Nagi Hirono, and Yuuko Amamiya. He shared a particularly close bond with Yuu, who once tasked him with investigating underclassman Yuuko Amamiya's strange conduct; Kuze discovered Yuuko was intimidating classmates and provoking fights to safeguard her possessions.

Kuze possesses black hair, usually tied in a ponytail with spiky bangs, brown eyes, and a slim, pale build. He stands 177 cm tall and weighs 61 kg. His typical attire features formal coats and dress shoes, complemented by hair ties, and he often carries his violin.

His personality merges outward charisma with inner cynicism. He projects animated optimism while functioning as a pragmatic realist. Openly a womanizer, he harbored admiration for Sumire Asou, his neighbor Renji Asou's mother, despite her marriage. While frequently performing selfless acts, these often concealed deeper motives. He maintained a protective, brotherly connection with Renji.

Roughly six months before Mizuki Hayama arrived in Otowa, Australia, Kuze received a terminal diagnosis. The anime identifies this as degenerative cardiomyopathy, while the visual novel refers to an unspecified neurosis. The prognosis was fatal, granting him less than a year. The progressive illness causes heart muscle atrophy, leading to weakness, eventual wheelchair dependence, and death. Daily medication only slows its inevitable progression.

Confronting his mortality, Kuze deliberately severed all personal ties, including with his fiancée, to spare others grief. He discarded belongings, burned letters (including one from Nagi), and isolated himself. This despair fueled conflicts with Yuu and Nagi.

During this isolation in Australia, Mizuki Hayama, visiting her aunt Sumire, reconnected with Kuze. They had first met years earlier when a young Mizuki was captivated by his street violin performance; Kuze gifted her his hair ribbon, calling her a "cute little lady." Now a teenager, Mizuki persistently sought him despite his rejections. After she confessed her love, Kuze distanced himself further, partly due to an attraction to her school uniform but primarily to avoid burdening her with his impending death. Nagi worsened the situation by falsely claiming an engagement to him.

Learning of his illness, Mizuki refused to leave. She challenged his isolation, declaring: "No matter how much you treasure them, all things eventually perish. Bonds, feelings, memories, hearts, and even life... So let's cherish it until that time." Her resilience and maturity shifted Kuze's perspective, helping him accept her support.

In his final arc, Kuze collapsed and was hospitalized. Choosing to face his fear of loss, he underwent high-risk surgery that extended his life by several years. He committed to cherishing his remaining time with Mizuki, agreeing to delay romantic involvement until she reached adulthood. This decision marked a transition from bitterness to peace as he focused on witnessing her growth.

Kuze's philosophy is captured in his advice to Mizuki: "When you get older, you’ll find the masks that you wear become part of the person you really are. As you get older, you need more people; you need more masks too."