Michi Akasaka is a female juvenile delinquent who serves as the leader of the Sumi Zero Ikka, the gang of sukeban, or female thugs, that controls Okutama High School. She initially appears as a minor antagonist driven by a deep grudge. Her hatred stems from an earlier encounter with Ryuji Hanaoka during his time with the Black Zeppelin gang. Because she claimed to know Monnojo Monda, Ryuji brutally beat her in the face with a wooden sword. Though her injuries eventually healed completely thanks to medical treatment, the humiliation and pain left her resentful toward both Ryuji and Monnojo.

Her motivations shift when Ryuji, now a member of the Reppuu-tai, chooses to make amends in a dramatic display of honor. He carves a large scar into his own face as a form of ketsume (taking responsibility for his actions). This act of self-sacrifice and masculine principle overwhelms Michi, causing her to forgive him and put the past behind her. This incident becomes the catalyst for a romantic relationship. She initiates a confession, and the two become a couple, at one point even being described as a silly, lovey-dovey pair known as a "baka couple."

Her role in the story is primarily that of a supporting character and love interest for Ryuji. She is part of the delinquent world but does not take part in the larger gang wars. Her key relationship is with Ryuji; through him, she becomes loosely connected to the main cast. Her personal development is limited but notable: she transforms from a vengeful gang leader into a devoted partner, showing that even hardened delinquents can be softened by genuine acts of honor and affection. Her notable ability is her leadership of the Sumi Zero Ikka, indicating she commands respect and fear from other students, and she is also shown driving a Daihatsu Cuore Turbo.