Taku Morisaki hails from Kōchi, initially residing near Mt. Godai with his parents before relocating to Tokyo for university. He has dark brown hair and brown eyes, often wearing his high school uniform of a white shirt and green tie or casual attire like a light pink shirt over a white T-shirt. Academically capable, his grades sometimes slip due to a part-time restaurant job funding school expenses, including a trip to Hawaii; this work causes teacher disapproval for missed classes. His personality mixes caring instincts with impulsiveness. He shows protectiveness towards Rikako Muto during her difficulties but reacts abruptly, like publicly confronting her after she hurts his friend Yutaka Matsuno or reciprocating her slap during an argument. Socially adept at maintaining friendships, he occasionally displays bluntness verging on tactlessness. His background features a six-year friendship with Yutaka Matsuno, forged in junior high when they jointly protested a cancelled school trip. Taku drafted a complaint arguing the cancellation merely eased adult frustrations, while Yutaka focused on its unfairness. This shared defiance cemented their bond, later tested in high school when both develop feelings for Rikako, a transfer student from Tokyo. Taku initially dismisses her as arrogant and unhappy but becomes involved after lending her ¥60,000 during the Hawaii trip. Discovering she used the money for a trip to Tokyo, he accompanies her when her original companion withdraws. There, he witnesses her familial conflicts, including disillusionment upon finding her divorced father prioritizes a new relationship over her. After sharing an overnight hotel stay where he offers her the bed and sleeps in the bathtub, rumors strain his friendship with Yutaka. Taku's interactions with Rikako grow contentious back in Kōchi. After Yutaka confesses rejection by Rikako, Taku confronts her in class, resulting in a mutual slap. Later, at a cultural festival, he observes her defending herself against bullying but refrains from intervening, commenting afterward that he admired her resilience—prompting her to slap him again. This leads Yutaka to punch Taku for failing to support her, fracturing communication within their trio for the rest of high school. All three attend different universities, with Taku enrolling in Tokyo and residing near Shakujii Park. Years later, at a high school reunion in Kōchi, Taku reconciles with Yutaka, who reveals he punched Taku out of frustration that Taku suppressed his feelings for Rikako to preserve their friendship. After the reunion, Taku learns Rikako skipped the event to visit Tokyo, intending to meet "someone who sleeps in bathtubs." While departing Tokyo's Kichijōji Station afterward, he spots Rikako across the platform. Recalling an earlier glimpse of her there, he runs to meet her; she waits instead of boarding her train, implying mutual recognition of lingering affection.