Mother-Son Copulation ~Journey Through the Highlands~ Special Release Edition includes 27 additional minutes of exclusive footage not found in the standard version, making the content even more intense. The original story follows Miyu, a former idol who raised her son alone as a single mother. After graduating college, her son moves to Tokyo, where by chance he discovers his mother's gravure photo book and falls deeply in love with her. When he returns home after a long absence, he finds his mother—having secretly indulged in daily masturbation—unable to resist her growing desire. Their familial bond collapses in an instant. After intense emotional conflict, Miyu surrenders her body, and the two cross the boundary of parenthood, deeply copulating at a traditional inn. The special edition enhances this experience with newly added scenes that portray their forbidden relationship with even greater realism.