Yuri Honma and her mother-in-law, Chisato, continue their daily power struggle through lesbian play. Using her voluptuous, soft body, Yuri challenges Chisato's skillful edging techniques, while Chisato attempts to maintain control with her calm, composed demeanor. After repeated encounters, Yuri finally calls Chisato out and proposes a new contest: female sumo. This match becomes the turning point that drastically changes their relationship.