At the son's request, mother and son visit a hot spring resort. Mother Chihiro is delighted that her son has been so filial to her, and they share a bath together. Bathing with his mother, the son's tired cock gets erect. Chihiro is mesmerized by his strong cock, and after the bath she indulges in masturbation. Still unable to forget about her son's cock, she approaches him and takes his large, erect cock into her mouth. Excited, mother and son get naked...