START-026 — My Girlfriend’s Best Friend Confesses Her Love—Our Double Affair Leads to Our First Creampie and Days of Nonstop Sex While Living Together — Ruu Totsuka

Ken and Mai are a couple who are close friends with another couple, Ruu and Jun. One day while Mai is away, Ken and Ruu have drinks alone. A drunken Ruu suddenly confesses that she has secretly loved him all along. Ken hesitates but eventually gives in to her advances, and the two begin a sexual relationship. With Mai gone for several days, Ken and Ruu start a brief life together behind both partners’ backs.