At the home of Tomomi, a 56-year-old grandmother, her 26-year-old junior coworker Tadashi suggests hosting a mixer by inviting friends over. Akina, a friend of Tomomi's, is also in her fifties and an exceptionally attractive mature woman. Tadashi is strongly attracted to Akina and clearly wants to get intimate with her. He actively pursues Tomomi, but Akina turns out to be an incredibly horny older woman who suddenly starts groping Tadashi's cock. Tadashi leaves Akina to his junior Makoto and heads to the bath with Tomomi. After a massage, they naturally enjoy sex together on the tatami floor.