Kaname Arisugawa, a 15-year-old high school student, assists in managing the Arisugawa Bathhouse alongside her older sister Aya. Tasked with daily operations and maintenance, she unhesitatingly cleans male bathing areas, embodying her direct, practical approach. Her connection to Nasa Yuzaki began in junior high, where she admired him as an upperclassman. This bond deepened after he aided the bathhouse during financial struggles, cementing her view of him as a paternal mentor. Cheerful and outgoing, Kaname playfully teases Nasa about his marriage to Tsukasa Yuzaki, openly discussing topics like romance and intimacy with bold humor inherited from her mother. Yet she balances this with mature insights, urging Nasa to strengthen his marriage through gestures like ceremonies or rings, prioritizing Tsukasa’s happiness. Driven by genuine curiosity and care, Kaname probes Nasa and Tsukasa’s relationship, sometimes observing their interactions. She affectionately nicknames Tsukasa “Tsukassan,” thanking her for saving Nasa’s life. Within her family, she lightheartedly needles Aya about her unguarded feelings for Nasa while supporting her sister emotionally. Juggling school and managerial duties, Kaname displays sharp organizational skills and pragmatism, evident when housing Nasa and Tsukasa after their apartment fire. Her interactions with the couple reinforce her belief in mutual sincerity as the foundation of lasting bonds. Blending youthful exuberance with perceptive wisdom, Kaname catalyzes Nasa’s growth through humor and thoughtful guidance, evolving into a steadfast friend who navigates life’s complexities with both levity and insight.