1girl, ass, bare_arms, bare_shoulders, black_one-piece_swimsuit, blonde_hair, blue_eyes, breasts, closed_mouth, competition_school_swimsuit, forehead, from_behind, jewelry, kofune_ushio, long_hair, looking_at_viewer, looking_back, medium_breasts, necklace, night, night_sky, omurice_(304975636), one-piece_swimsuit, outdoors, school_swimsuit, shell, shell_necklace, sky, summertime_render, swimsuit, very_long_hair, wading, water