Masamune Matsumoto is a student appearing in the comedy series High Score. He stands at approximately 193 centimeters tall with black hair and green eyes. He is best known as the boyfriend of Fujiwara Megumi, a beautiful yet selfish and violent high school girl, and he is also the older brother of Emika. His personality is defined by an intense narcissism; his email address reflects this self-obsession, and he is frequently preoccupied with his own appearance and image. Beneath this vanity, however, he displays moments of surprising reasonableness and even endearing qualities. He has a notable fondness for pudding and will enthusiastically watch television specials about new pudding products, revealing a whimsical, almost childlike side. He is also good with children and shows a caring attitude toward them. In the story, Masamune functions as one of the recurring figures in the chaotic school environment, primarily through his relationship with Megumi. Although he is her official boyfriend, Megumi often flirts with or pursues other boys, which creates a dynamic where Masamune is sometimes caught up in her unpredictable and violent antics. His connection to Emika, his sister, also plays a role in the series' interpersonal conflicts, as she sometimes involves him in her schemes regarding her brother Kyosuke. Masamune's development is subtle rather than dramatic, with the series focusing on his consistent traits—narcissism paired with unexpected softness—rather than a major character transformation. His notable abilities are not superhuman or combat-oriented; instead, his defining attributes are his extreme self-regard, his capacity for maintaining a relationship with a domineering partner, and his quirky, innocent tastes that contrast with his vain exterior.