Kiri's design would look more balanced if her shirt had blue trim matching her skirt. Mii has a cool and distinctive outfit, but the hair makes her look too much like Miku although Mii doesn't have the exact hair color as Miku. It's the combination of long teal hair with that style of hair accessory, and the way the front of her hair is styled. If she had a different style of hair accessory, it wouldn't seem so similar, and if her hair were shorter or longer, or weren't in pigtails, or the front of her hair was styled differently.