1girl, ahoge, bikini, blue_sky, blush, breasts, cleavage, hair_ribbon, half-closed_eyes, hand_on_own_cheek, hand_on_own_face, ichinose_shiki, idolmaster, idolmaster_cinderella_girls, large_breasts, looking_at_viewer, nys, outdoors, partially_submerged, pink_bikini, pink_innertube, purple_hair, reflection, reflective_water, refraction, ribbon, sky, smile, solo, swimsuit, twintails, wavy_hair, wrist_cuffs