Hakkai is shown to be a timid but friendly guy. He freezes up around women and gets very nervous and awkward. 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. His eyes are indigo, and he has a noticeable scar on the left side of his lip. He wears a concentric teardrop earring on his left ear. Has an older sister named Yuzuha and an abusive older brother named Taiju. Childhood friend is named Mitsuya.