A couple married to their childhood friend four years their senior. Raised in the countryside, they grew apart temporarily when attending different universities, but reunited as adults and tied the knot. Even after marriage, they maintained a platonic, friendship-like relationship, both indifferent toward sex. However, in their 25th year of marriage, the husband suddenly confessed to his wife that he harbored a desire to be cuckolded. After much inner turmoil, the wife resolved to accept another man's cock. Over time, this arrangement gave rise to unexpected new emotions.