Mana Makihara visits the family-run inn managed by her father-in-law, Yukio, under the pretext of paying respects at her mother-in-law's grave. Raised in the city, Mana finds herself immersed in the lush natural surroundings and soothing hot springs, gradually letting her guard down both mentally and physically. Drawn to her growing allure, Yukio becomes acutely aware of his long-dormant desires and can no longer resist sneaking into Mana's room at night. As he passionately caresses her and thrusts into her body, she resists at first—but deep down, she begins to feel undeniable pleasure. The sensation of him penetrating deep inside her lingers well into the next morning, awakening something within her that can never be undone.