4girls, arms_up, ball, beach, beachball, bikini, black_bikini, black_ribbon, blue_eyes, blue_sky, breasts, butterfly_hair_ornament, cloud, day, fishing_rod, go-toubun_no_hanayome, hair_ornament, hair_ribbon, hand_in_own_hair, hands_in_hair, large_breasts, multiple_girls, nakano_ichika, nakano_itsuki, nakano_nino, nakano_yotsuba, navel, ocean, orange_hair, outdoors, pink_hair, poa_mellhen, red_hair, ribbon, short_hair, siblings, side-tie_bikini_bottom, sisters, sitting, sky, solo_focus, stomach, swimsuit, thighs, tying_hair