tsukasa jun, mifune nagisa, sister mermaid, game cg, 1girl, 3d, :d, armpits, ass, back, bag, beach, blue eyes, blue hair, blush, bow, breasts, covered erect nipples, earrings, female focus, hair bow, jewelry, large breasts, lipstick, long hair, looking at viewer, looking back, lying, makeup, matching hair/eyes, on stomach, one-piece swimsuit, one-piece thong, open mouth, outdoors, parasol, ponytail, profile, sand, shadow, sideboob, slingshot swimsuit, smile, solo, swimsuit, towel, umbrella, underboob, white one-piece swimsuit