1girl 1other alternate_costume alternate_hairstyle bangs bare_shoulders bikini black_bikini blue_eyes blush collarbone cropped_legs double_bun frilled_bikini frills ghost goggles goggles_on_head hair_bun halterneck hand_on_hip hikimayu holding holding_innertube innertube kokaki_mumose kuroshio_current looking_at_viewer navel open_mouth red_innertube simple_background single_wrist_cuff sketch smile stomach swimsuit third_eye toudouin_mana upper_body v-shaped_eyebrows white_background wrist_cuffs