Upon hearing that Umi, his mother's friend who used to tutor him during his school days, had returned to their hometown after a long absence, Kazuya was overwhelmed with uncontrollable joy and anticipation. Reunited, Umi remained as beautiful as ever, her charm undiminished by time—indeed, she seemed to shine even brighter. Aware of her presence, Kazuya found his long-held feelings for her growing ever stronger. Unable to suppress his passion any longer, it soon took physical form, and the two plunged into a forbidden relationship. Umi, too, found her heart captured by his intensity, and the emotions between them deepened rapidly. Yet her words lingered in his mind: such an extraordinary relationship might not last forever.