[P.A. Project (Teruki Kuma)] Ichiban Sentou [biribiri]

Two young sisters share an innocent soak in the tub until an unexpected guest — their older brother — stumbles upon them, sparking a chaotic, steamy chain of events. A accidental taste of dirty bathwater escalates into a delirious double dose of oral play and a three-way splash party that leaves everyone gasping and dripping wet.