4girls, ;d, adapted_costume, animal_ears, arimoto_wataru, beach, bikini, bikini_skirt, black_hairband, blonde_hair, blush, breasts, cleavage, dutch_angle, front-tie_bikini_top, front-tie_top, green_eyes, green_skirt, hairband, hakui_koyori, holding, holding_water_gun, hololive, horse_ears, kazama_iroha, kazama_iroha_(1st_costume), medium_breasts, multiple_girls, navel, ocean, one_eye_closed, open_mouth, outdoors, ponytail, sakamata_chloe, skirt, smile, solo_focus, swimsuit, takane_lui, virtual_youtuber, wading, water, water_gun, white_bikini