1girl, alternate_costume, animal_ear_fluff, animal_ears, arms_behind_back, bare_shoulders, black_hair, black_sports_bra, blue_archive, breasts, cat_ears, collarbone, halo, ku_roiko, long_hair, looking_at_viewer, navel, ponytail, red_eyes, serika_(blue_archive), simple_background, small_breasts, solo, sports_bra, stomach, underwear, upper_body, white_background