Mark-kun catches a cold and is unable to join his family on vacation, leaving him behind with his cousin, an older sister figure. As she gently nurses him back to health, her warmth captivates his heart—yet his lustful fantasies won't subside. The story takes an enticing turn when friends come over, leading to a wild and uninhibited threesome. The intimate scenes between Mark-kun, feverish and suffering, and the caring big sister further shake his emotions. Her voluptuous, big-titted body glistens with sweat as she carefully performs a titty fuck, creating an erotic dreamlike atmosphere. A special moment where warmth and sensuality blend perfectly.