During her husband's work-related absence, Yuna grows increasingly lonely and sexually frustrated, developing intense feelings for her nephew Ittoku, who lives with her. Drawn to his strong, masculine physique, she begins to see him as a man. Unable to suppress her emotions, Yuna starts seducing Ittoku with provocative gestures and suggestive words. Though Ittoku is shaken by her advances and tries to maintain self-control, he can't deny the growing excitement within him. At dawn, spotting Ittoku in the shower, Yuna sneaks up behind him, presses her naked body against his, and embraces him tightly. In that moment, a new, forbidden relationship begins between them.