1girl, beach, bikini, blurry, blurry_background, brown_eyes, day, hood, hoodie, idolmaster, idolmaster_cinderella_girls, koshimizu_sachiko, navel, ocean, outdoors, purple_hair, red_bikini, sakaki_imasato, short_hair, side-tie_bikini_bottom, sleeves_past_fingers, sleeves_past_wrists, solo, swimsuit