Mamatachi No Himitsu 01 — Mama Katsu Midareru

The mama-katsu women, including Yumi and Rie, start to explore their hidden desires, testing the boundaries of their marriages, friendships, and the very concept of "mama-katsu."

The phrase refers to the first volume of a Japanese manga or adult-oriented media title. Title Breakdown : mama katsu midareru mamatachi no himitsu 01