1girl, animal_ears, bare_shoulders, bed, breasts, cleavage, collarbone, ear_ornament, greyscale, hair_in_own_mouth, horse_ears, horse_girl, lingerie, long_hair, looking_at_viewer, loose_hair_strand, lying, medium_breasts, mejiro_ardan_(umamusume), monochrome, mp4_46, on_side, pillow, pov, smile, solo, strap_slip, sweat, umamusume, underwear