1girl, d, beach, bikini, cloud, collarbone, frilled_bikini, frills, grey_eyes, grey_hair, idolmaster, idolmaster_cinderella_girls, looking_at_viewer, navel, off-shoulder_bikini, off_shoulder, open_mouth, otokura_yuuki, outdoors, sand, short_hair, sky, smile, solo, stomach, swimsuit, water, yuukura_yuu