1girl, alternate_costume, animal_ears, bikini, black_hair, blush, breasts, cleavage, cloud, collarbone, daring_tact_(umamusume), horse_ears, horse_girl, horse_tail, kouzuki_hajime, medium_breasts, medium_hair, navel, ocean, open_mouth, outdoors, sky, solo, stomach, swimsuit, tail, umamusume