On a rainy afternoon, siblings Aki and Sora Aoi revealed their mutual affection, beginning a clandestine romance. Unaware that his heart belongs elsewhere, Sora"s twin sister Nami encourages him to join the school"s Fashion Research Club in hopes of pairing him with classmate Kana Sumiya. Yet Nami"s well‑meaning gesture conceals a painful secret: while she pretends to be a supportive sister aiding her brother"s search for love, she secretly nurtures forbidden emotions of her own. Her hidden longing threatens to unravel the balance between sibling loyalty and personal desire.