2girls ball beachball bikini blonde_hair blue_hair blush cloud collarbone commentary_request day fang flat_chest furude_rika hairband higurashi_no_naku_koro_ni houjou_satoko kazura long_hair multiple_girls navel one-piece_swimsuit open_mouth outdoors outstretched_arm outstretched_hand purple_eyes short_hair sky standing string_bikini swimsuit wading water