Hakkai is a teenager of above-average height with royal blue hair styled in a crew cut. A swirl design is shaved on the left side of his head, extending to the back of his head. His eyes are an indigo color, and he has a noticeable scar on the left side of his lip. He wears a concentric teardrop earring on his left ear. 14 years old, 1m83 tall. Weighing 78kg, he is very shy. Every time a strange girl talks to him then he will freeze. He is blood type O, and was born on September 4th.