Photorealistic full body shot, naked 20 year old Blond Caucasian woman, slender physique, big saggy flattened breasts, lying relaxed in a traditional Japanese onsen, night, candles and lanterns giving off a warm glow, body partially submerged in hot steaming water, thick wet pubic hair, masturbating, fingering her pussy, head resting on a smooth dark stone edge of the pool, serene facial expression, accurate detailed eyes, piercing gaze, hyper-realistic skin texture, visible pores, water droplets on skin, soft ethereal haze, thick foggy atmosphere, natural outdoor hot spring setting, mossy rocks, soft diffused daylight, muted warm tones, cinematic lighting, high resolution face, masterpiece, 8k UHD, sharp focus, hyper-detailed, extremely detailed, photorealistic, depth of field, Fujifilm XT4, 85mm lens