1girl, arm_warmers, armpits, ass, bikini, blue_bikini, brown_eyes, brown_hair, cloud, eluthel, from_behind, idolmaster, idolmaster_cinderella_girls, leaning_forward, long_hair, looking_back, open_mouth, outdoors, shirt, sky, smile, solo, swimsuit, tachibana_arisu, thighs, twintails, wading, water, white_bikini, white_shirt