Sentarou Miya is a light-haired, brown-eyed student at Hakuto High School. His short stature frequently causes others to mistake him for a middle schooler, a constant source of frustration. Sentarou possesses a hot temper, flaring up quickly, especially when his height becomes the target of jokes or comments. Yet beneath this volatile exterior lies emotional vulnerability, making him prone to easy tears. He struggles significantly around girls, experiencing physical reactions like nosebleeds, as seen in his encounters with Satowa Hozuki. Family reveals another side: Sentarou regularly visits his grandmother outside school breaks and takes responsibility for looking after his younger sister, hinting at a caring nature. Sentarou actively enjoys yakiniku, associating it with masculinity and stating it's a natural food for men. Conversely, he dislikes green peas and beans. On holidays, he dedicates time to physical training, focusing on conditioning. His surname, Miya, translates to "temple," "shrine," or "palace." His given name, Sentarou, combines the characters for "thousand" (千), "thick," "big," or "great" (太), and "melodious," "clear," "bright," "serene," or "cheerful" (朗), reflecting potential cheerfulness despite his fiery temperament.