1girl, o, arknights, bikini, black_bikini, blue_eyes, blue_sky, blush, bracelet, brown_hair, flat_chest, hair_ornament, hairclip, hand_up, jewelry, looking_at_viewer, navel, official_alternate_costume, one-hour_drawing_challenge, parted_lips, reiya_(aisunokappu), short_hair, short_twintails, sky, solo, stomach, sussurro_(arknights), sussurro_(summer_flower)_(arknights), swimsuit, twintails, upper_body, x_hair_ornament