Kiko Hikizuri, one of six siblings inhabiting a strange, unsettling household shadowed by their parents’ deaths, navigates her role as an older sister amid the family’s fractured dynamics and lingering grief. Her jealousy surfaces sharply when her brother Shigaro observes that their sister Narumi bears a closer resemblance to their late mother, betraying a fragile ego and craving for validation within the family’s fragile hierarchy. The siblings’ relationships, marked by tense power struggles and a shared reluctance to confront responsibility, spiral around their youngest sister Misako’s violent outbursts. Kiko’s complicity in these dynamics mirrors the siblings’ collective failure to heal their shared trauma, perpetuating cycles of emotional neglect and bitter rivalry. Her choices and reactions unfold against the siblings’ strained efforts to assert control as their environment decays, though her personal evolution outside these entangled conflicts remains undefined in existing records.