1girl, animal_ears, bow, breasts, brown_dress, brown_footwear, buttons, double-breasted, dress, dusu_(htkj), ear_covers, happy_birthday, horse_ears, horse_girl, horse_tail, juliet_sleeves, long_sleeves, looking_at_viewer, medium_breasts, medium_hair, multicolored_hair, nice_nature_(umamusume), puffy_sleeves, red_hair, simple_background, solo, streaked_hair, striped, striped_bow, tail, thigh_strap, twintails, umamusume, white_background