happy birthday (artist), maruchan., original, 1girl, ahoge, arm up, armlet, blonde hair, blue eyes, blush, fang, female focus, frilled sleeves, frills, gradient background, hair between eyes, hair bun, hand on own head, happy birthday, jewelry, long sleeves, looking at viewer, open mouth, pink ribbon, ribbon, sailor collar, school uniform, serafuku, shirt, simple background, single hair bun, smile, solo, upper body, white shirt