1girl, ahoge, blue_archive, blue_one-piece_swimsuit, covered_navel, hair_ornament, hairclip, hina_(blue_archive), hina_(swimsuit)_(blue_archive), horns, innertube, legs_apart, long_hair, lying, m-eine, name_tag, on_back, one-piece_swimsuit, one_side_up, open_mouth, pink_eyes, school_swimsuit, solo, swimsuit, thighs, very_long_hair, white_hair