1girl, beach, bikini, black_hair, blush, breasts, cloud, collarbone, day, frilled_bikini, frills, groin, hand_on_headwear, hat, holding, holding_innertube, horizon, idolmaster, idolmaster_cinderella_girls, innertube, light_smile, looking_at_viewer, navel, outdoors, palm_leaf, sasaki_chie, short_hair, side-tie_bikini_bottom, small_breasts, smile, solo, stomach, straw_hat, swimsuit, tsunenorip, wading