Zao is an Super Type A Cruiser class or a B 65 Cruiser along with his brother Senjo, Kunimi, Unzen. Zao is Terrified Azuma which is another B 65 Cruiser but stronger than him. Zao is been called the Assasin Cruiser since he have an Assasin Capabilities. Azuma doesn't have a Problem with it. Azuma and Zao is in Relationship.