1girl, 2015, backless_dress, backless_outfit, black_dress, blush, breasts, brown_eyes, brown_hair, bug, butterfly, character_name, dated, dress, from_behind, happy_birthday, holding, holding_microphone_stand, kisaragitsubasa, large_breasts, meiko_(vocaloid), microphone_stand, open_mouth, project_diva_(series), red_headwear, short_hair, shoulder_blades, sideboob, solo, vocaloid