Miharu Sekiguchi is the younger sister of the protagonist Shota Sekiguchi. She lives in Otaru, Hokkaido, with her parents, who both struggle with health problems: her mother suffers from a chronic illness and her father Genji is injured. As a typical younger sister figure in the household, she takes on most of the domestic chores, keeping the family home and the small sushi shop Tomoe Sushi running while her brother trains in Tokyo. Her primary motivation is to see Shota succeed as a sushi chef so he can return and rebuild the family business. She endures the business pressures from the large chain Sasa Sushi and waits patiently for his growth, providing a steady emotional anchor for the family. Her role in the story is that of a supportive background character, representing the home front that Shota aims to save. She maintains a close, caring relationship with her brother, encouraging his efforts from a distance, and also looks after her ailing parents. Over the course of the series, she remains a constant presence, her responsibilities deepening as the family’s struggles continue. Her notable abilities lie in household management and the practical care of the family, ensuring that the home and shop remain intact during Shota’s absence.