3girls, aged_down, alternate_breast_size, animal_ears, bag, barefoot, black_one-piece_swimsuit, blonde_hair, blush, breasts, bright_pupils, brown_eyes, brown_hair, cat_ears, collarbone, competition_swimsuit, feet, flower, hair_flower, hair_ornament, hand_on_own_chin, height_difference, holding, holding_bag, long_hair, looking_to_the_side, medium_hair, misaka_imouto, misaka_mikoto, multicolored_clothes, multicolored_swimsuit, multiple_girls, one-piece_swimsuit, shokuhou_misaki, siblings, simple_background, sisters, small_breasts, sparkle, sparkling_eyes, star-shaped_pupils, star_(symbol), sweat, swimsuit, symbol-shaped_pupils, teruya_(6w6y), toaru_kagaku_no_railgun, toaru_majutsu_no_index, toaru_majutsu_no_index:_new_testament, tokiwadai_school_swimsuit, two-tone_one-piece_swimsuit, two-tone_swimsuit, yellow_pupils