1girl, arknights, bare_shoulders, black_choker, blue_sky, breasts, choker, cleavage, collarbone, criss-cross_halter, day, hair_ornament, hair_rings, halterneck, horns, long_hair, looking_at_viewer, medium_breasts, mutsuki_albino, official_alternate_costume, outdoors, parted_lips, purple_eyes, red_hair, sky, solo, star_(symbol), star_hair_ornament, surtr_(arknights), surtr_(colorful_wonderland)_(arknights), swimsuit_cover-up, upper_body