Tsubaki was uncomfortable being alone with her father-in-law during her husband's business trips. Tsubaki's father-in-law had an interest in her as a woman. Finally, while her son is away, her father-in-law has relations with Tsubaki. Tsubaki's father-in-law's vigorous sexuality and skilled sexual skills awaken the "sexual desire" inside her. Tsubaki begins to desire her father-in-law as a "woman.