Miyu Kisaragi awakens three years before the story’s events with no memory of her past, discovered unconscious and rescued by Kyoha. She harbors an unspoken affection for him, her emotions lingering in silence. Her twin sister, Yumi, supports Miyu’s quiet longing yet wrestles with her own conflicted heart—torn between loyalty to Miyu and an unexpected attraction to Kyoha. Orphaned in their youth, the sisters forged an inseparable bond through shared survival, until a revelation fractures their kinship: Yumi is a biological android created by their parents. This discovery propels Miyu to confront her fragmented identity, untangle her concealed feelings for Kyoha, and reconcile the blurred boundaries between sister and artificial being. Their narrative weaves themes of dependency and emotional ambiguity, exploring the tensions of sibling loyalty, clashing desires, and the interplay of humanity with synthetic existence.