1girl, o, ass, bare_shoulders, blonde_hair, blush, casual_one-piece_swimsuit, chiyosuke_(nosuke21), cowboy_shot, frilled_one-piece_swimsuit, frills, from_behind, green_eyes, halterneck, hat, hat_ribbon, idolmaster, idolmaster_cinderella_girls, innertube, looking_at_viewer, looking_back, one-piece_swimsuit, ribbon, sakurai_momoka, short_hair, solo, sun_hat, swimsuit, wading, water, white_background, white_headwear, white_one-piece_swimsuit