Yui

The AI who Turned Real. Yui is a former AI for the Cardinal System that was designated MHCP001. At the start of Aincrad Infinity, Yui is contained within an object known as "Yui's Heart". When she is freed from Yui's Heart, she becomes a Player, gains a new appearance, and gains true intelligence.

Appearance
Original=Yui's original appearance was that of a young girl with long, black hair and black eyes. Her "default" outfit consisted of a white dress with half sleeves and a white ribbon tied around her waist. Yui went barefoot in her default outfit.
 * -|New=Yui's appearance changes after being freed from Yui's Heart in Infinite Aincrad. She becomes taller and looks older, gaining the appearance of an eight-year-old instead of a six-year-old. Her hair becomes a darker black and her eyes turn a hazel color. Her equipment in Infinite Aincrad consists of a dark gray skirt and a long-sleeved, light pink shirt under a silver-colored breastplate. She wears knee-high, light brown boots as shoes. She tends to keep a light pink ribbon tied to the end of a single braid on the right side of her head.