Shibata Masami is Masayoshi's older brother. He is kind and caring, always putting others, especially his little brother, before himself. When his and Masayoshi's mother died their father moved with them to Japan, where Masami took it upon himself to take care of his brother and father, often exhausting himself. He met Hagiwara Tooru at that time, who he developed feelings for.

His and Masayoshi's father is Japanese, while their mother, who died when the brothers were young, was Norwegian. Their father lives in Norway with their grandmother, while the brothers live together in Japan.