1girl, bare_shoulders, bikini, blush, breasts, brown_eyes, brown_hair, cleavage, closed_mouth, collarbone, dated, hair_between_eyes, hands_up, happy_birthday, heart, hibike!_euphonium, looking_at_viewer, medium_breasts, midriff, navel, oumae_kumiko, short_hair, smile, solo, standing, swimsuit, tsuji643163271, white_bikini