Mito Mitsukuni, a diminutive alien from a species with gender determination during puberty and lifespans surpassing ten millennia, embodies a paradox of childlike appearance and seasoned adulthood. As a notorious space pirate, her bold demeanor and combat expertise mask a deeply personal mission: protecting her half-human son, Aoi, unaware of her extraterrestrial origins. To bridge their worlds, she dons a powered exosuit, the "Mail Suit," disguising herself as a human woman while navigating motherhood and interstellar skirmishes.

Her past intertwines with Earth through Kagero, her late human husband, whose legacy she upholds amid galactic turmoil. Juggling piracy and parenthood, she clashes with the Galactic Patrol, shielding Aoi from cosmic strife while grappling with unresolved grief. This duality intensifies when Aoi’s species-inherited gender instability culminates in his transition and ascension as galactic queen, thrusting Mito from renegade life into the political arena as his court soldier. Their evolving relationship oscillates between conflict and unity, mirroring their shared struggle to reconcile personal identity with external expectations.

A master swordsman and tech-savvy combatant, Mito wields a pulse rifle and her Mail Suit’s enhanced capabilities, though its vulnerable back sensor poses a critical weakness. Her species’ biology not only shapes Aoi’s transformative journey but also underscores themes of biological determinism versus self-definition. Alliances with figures like Galactic Patrol officers Mutsuki and Masatsuki Nenga reveal her tactical ingenuity, balancing outlaw defiance with reluctant diplomacy.

Her narrative weaves maternal loyalty against rebellious instincts, testing allegiances to family and crew. Over time, her influence etches into galactic history, her actions seeding political evolution long after her piracy fades, cementing her as both a mythic founder and a complex figure straddling legacy and survival.