1girl, 3, animal_ears, bare_shoulders, breasts, brown_hair, christmas, cleavage, closed_mouth, detached_sleeves, hair_over_one_eye, holding, holding_key, horse_ears, horse_girl, inaba_(usanopo), key, large_breasts, looking_at_viewer, lying, on_side, pillow, red_eyes, red_sleeves, short_hair, sirius_symboli_(umamusume), smile, solo, umamusume, upper_body