Kosuke Inukai, a fourth-year undergraduate in Saitama University’s Ikeda Laboratory, sports blond hair, brown eyes, and chest-length locks accentuated by earrings. His self-fashioned image as a charismatic ladies’ man, complete with boasts about a longtime girlfriend named Aika, cloaks a secret obsession: Aika is a character from his favorite dating simulation game. To protect this identity, he meticulously conceals his trove of 2D merchandise—figurines, body pillows, and more—from judgmental eyes. His childhood friend, labmate Ena Ibarada, shares his passion for video games, their bond laced with unspoken tension. Though Ena’s likeness to the protagonist of his beloved games lingers in his periphery, Kosuke sidesteps acknowledging the parallel. Outwardly aloof and blunt, he masks a quiet sensitivity, tentatively lowering his guard to express care for peers while wrestling with insecurities about his social persona. In the lab, Kosuke’s technical prowess in robotics and mechanics shines through inventive device designs that streamline experiments. His ISTJ-driven adherence to protocols and efficiency balances a reserved demeanor, yet cracks in his composure reveal anxiety over exposed hobbies or social missteps. Support from peers like Yukimura, who validate his passions, steady his shaky confidence. Kosuke’s journey inches toward self-acceptance as he mentors juniors and collaborates on projects, proving his otaku interests need not hinder his scientific rigor. Subtle shifts—opening up about his hobbies, engaging more openly with peers—hint at growth. He clings to soccer-themed attire, a vestige of abandoned athletic pursuits, and steals naps in the lab between tasks. These quirks, paired with his evolving emotional transparency, paint a portrait of a man straddling the worlds of calculated innovation and guarded vulnerability.