Yui Saotome and her sister, both fresh-faced and innocent, step into their traditional Japanese bath, the warm water caressing their bare skin. They start to wash each other, their hands lingering longer than necessary, their breaths hitching as they realize the tension between them. Yui's sister tentatively reaches out, tracing her fingers along Yui's inner thigh, making Yui gasp. The sisters lock eyes, understanding passing between them, as they begin to explore each other's bodies, their soft sighs filling the quiet room. They take their time, learning each other's pleasure points, their bodies pressed together, their hips moving in sync as they bring each other to a shared orgasm.