This man is Haiji's Father.
Personality
When Haiji was a kid, he berated him for wanting to become a doctor instead of an assassin.[1]
Appearance
He has long, back length hair, and is wearing black trousers.[1]
Background
He sired a child named Haiji. When his child was younger, he berated him for his decision to becoming a doctor instead of an assassin. He went onto say that he will turn his son into "my finest assassin protege"."
His current status is unknown.