Mitsuki Aasu, third youngest among the seven Aasu sisters bound by duty to protect Earth, juggles high school with managing her siblings’ household. Financial strain fuels her covert yearning for prosperity, a desire sharpened by daily frustrations. Her pragmatic resolve often clashes with Itsue, a sister who redirects her dominatrix frustrations onto Mitsuki during client droughts. Yet Mitsuki endures, balancing familial friction with unwavering focus on her responsibilities and ambitions.

As a defender, she wields Earth Acceleration, a power granting unmatched sprinting speed rendered tactically useless by its chaotic, uncontrollable direction—a flaw mirroring her sisters’ similarly defensive yet impractical abilities. Nights unveil a peculiar quirk: Mitsuki sleepwalks as an ax-wielding lumberjack, loudly demolishing phantom trees, a surreal contrast to her daytime tensions.

Amid accusations of triggering household explosions, she defiantly rejects attempts to blame her biology, refusing reduction to stereotypes. The Aasu lineage, marked by numerical names descending from seven, anchors Mitsuki in generational duty. Yet her story orbits around personal battles—navigating impractical powers, financial burdens, and a hunger for self-determined success within the chaos of sisterhood.