Kousuke Kanzaki is an eighteen-year-old high school student and a skilled calligrapher. He became interested in calligraphy after attending an exhibition by Seishuu Handa, whom he came to idolize and whose work inspired him to take up the art himself. Kosuke's talent is considerable; he has won first prize in a calligraphy competition, establishing himself as a promising young artist. His personality is energetic and generally friendly, but he also tends to be hotheaded and sarcastic, a side that emerges especially during his first encounters with Handa. Kosuke's primary motivation is his ambition to succeed and gain recognition for his work, which initially manifests as a rivalry with Handa. He wants to surpass the calligrapher he admires and prove his own abilities. This drive leads him to travel to the Goto Islands together with Handa's friend Kawafuji, seeking to meet Handa in person. As a character, Kosuke's role evolves from an enthusiastic fanboy and competitive rival to a more nuanced acquaintance. His relationship with Handa is marked by initial tension due to Kosuke's bluntness and competitive attitude, but as he observes Handa's life on the island and interacts with him, he develops a deeper understanding of both Handa and his own craft. Over the course of the story, Kosuke shows development by learning to temper his ambition with humility and gaining a more mature perspective on calligraphy. His notable abilities include his technical skill as a calligrapher, which has earned him recognition at a young age, and his determination to grow and improve.