1girl, arm_support, bad_twitter_id, bare_legs, beach, bikini, black_bikini, blonde_hair, blue_eyes, blue_sky, breasts, cleavage, cloud, day, horizon, idolmaster, idolmaster_cinderella_girls, knee_up, lamp_p9, large_breasts, long_hair, looking_at_viewer, navel, ohtsuki_yui, on_ground, outdoors, reflection, reflective_water, refraction, sideboob, sitting, sky, solo, swimsuit, very_long_hair, water_drop, wavy_hair