2girls, amasawa_yuuko, arm_up, armpits, bikini, brown_eyes, brown_hair, casual_one-piece_swimsuit, dennou_coil, dog, fish, frilled_bikini, frills, frown, goggles, grass, hand_on_own_forehead, knee_up, long_hair, looking_at_viewer, lying, multiple_girls, navel, okonogi_yuuko, on_back, one-piece_swimsuit, sasaki_bullet, short_hair, sitting, smile, swimsuit, twintails, water