Due to an unexpected accident, her husband is hospitalized, leaving Mizuki increasingly frustrated and sexually unfulfilled in her daily life. Her husband's best friend, Tetsuro, steps in to help with household chores and heavy tasks. As Mizuki gazes at Tetsuro's strong, masculine physique, she finds herself irresistibly drawn to him. That night, she loses control of her senses, indulging in lewd fantasies about him. In the heat of the moment, her fingers begin to move on their own—just as she's about to climax, something unexpected happens. Tetsuro, who was supposed to have left, stands right before her.