Kana Minami is the middle sister in the Minami family and is a second-year student in junior high school. Her name contains the kanji character for "summer," which aligns with the seasonal naming pattern shared by her siblings. As the middle child, she serves as a bridge between her responsible older sister, Haruka, and her sharp-tongued younger sister, Chiaki.

Kana's personality is defined by her impulsive, energetic, and mischievous nature. She is a quintessential "act first, think later" individual, often diving into situations without considering the consequences. Her liveliness makes her a natural source of chaos and comedy within her household. She frequently invents random new holidays and enjoys dragging others, including Chiaki's elementary school friends, into her silly escapades. Despite her outward carefree demeanor, there are hints that she is more perceptive than she lets on, and she is capable of manipulating situations and the people around her to maximize her own entertainment.

Her primary motivation is to have fun and avoid boredom, which she achieves by teasing her sisters and concocting elaborate pranks. She has a strong, albeit often unspoken, desire for her sisters' approval and is privately hurt when they dismiss her as simply foolish. She longs for Chiaki to treat her as an adorable older sister, though her antics usually provoke the opposite reaction. This dynamic forms the core of her interactions, as she enjoys pushing Chiaki's buttons, leading to a constant cycle of teasing and retribution.

Within the family structure, Kana treats her eldest sister Haruka less as a mother figure and more as an older sibling to be teased and manipulated, a dynamic likely shaped by their longer history living together before their parents' absence. Her relationship with Chiaki is the most volatile; Kana often serves as the straight man's foil, acting outlandishly while Chiaki responds with cynical remarks and physical comebacks. However, beneath the bickering lies a genuine, if rarely expressed, affection. In moments of vulnerability, such as when Chiaki has a nightmare, Kana provides comfort, demonstrating the deep bond they share.

Kana's role in the story is primarily that of an instigator. Her actions and misunderstandings drive many of the slice-of-life plots, turning ordinary days into humorous events. Her relationships extend beyond her family. She has a notable connection with her classmate Fujioka, who has a crush on her. Kana, however, has been misled by Chiaki into believing Fujioka holds a grudge against her, leading her to misinterpret his romantic advances as challenges or threats. Despite this confusion, she frequently invites him to her home, and he becomes a regular fixture in the Minami household. She also enjoys spending time with her younger sister's friends, particularly delighting in recruiting the gentle-natured Makoto into her schemes, which famously included convincing him to cross-dress.

While Kana shows little development in her academic or domestic skills, she is a poor student with no patience for studying, and her cooking is notoriously terrible. She is prone to "improving" recipes with disastrous results, such as adding orange juice to pancake mix or chili peppers to bathwater. Despite these consistent flaws, there are moments that suggest a hidden potential for growth, such as when she earns a near-perfect score on a math test, indicating that she is capable of applying herself when properly motivated. Her notable abilities lie not in book smarts but in her social engineering and her boundless, infectious energy, which ensures that life in the Minami household is never dull.