1girl, d, armpits, arms_up, black_one-piece_swimsuit, breasts, collarbone, competition_swimsuit, covered_navel, hiroki_(yyqw7151), holding, holding_innertube, innertube, looking_at_viewer, one-piece_swimsuit, ootori_emu, open_mouth, pink_eyes, pink_hair, project_sekai, short_hair, simple_background, small_breasts, smile, solo, swimsuit, white_background