Hakkai is a very tall and lanky teenager with blue hair that is cut to a crew cut and shave hair art on the left side of his head. He wears a unique ear earring that seems like a fan on his left ear. He has a noticeable scar on the left side of his lip.
- The name Hakkai means "eight commandments" (八戒).
- Hakkai's surname Shiba means "brush, firewood" (柴).