Mina Shinbashi, one of the three Shinbashi sisters, shares a significant childhood history with Jun. Her parents' divorce led her to move away with her father, causing a separation from Jun and her sisters. Following her father's death, she returns to live with her sisters, reappearing in Jun's life as he searches for meaningful connection.

Mina's fiery red hair is as striking as her sharp tongue. She often masks deeper emotions with a brusque or confrontational demeanor. A tense first encounter with Jun on a train, where he mistakenly gropes her, cements her view of him as a pervert. This incident drives her to protect her sisters from what she perceives as his threatening advances.

Beneath her critical exterior lies vulnerability. Her return coincides with the discovery of a serious heart condition requiring surgery. This health crisis highlights her emotional complexity, revealing fear and fragility that contrast with her assertive, protective nature. She must navigate this personal challenge while dealing with evolving feelings for Jun.

Mina's relationship with Jun transforms from hostility to a deeper bond as he learns of her health struggle and supports her. This shift turns her from an antagonist into a central emotional focus in Jun's quest for love, underscoring her importance beyond first impressions.