Voice texture would be Deep, rich, and gravelly with a grounded resonance that gives the character weight and authority. There’s a gravitas to the way he speaks, almost like each word is deliberate and laced with restrained power. Tone and Delivery should be 

Calm but menacing, with emotional control. When he raises his voice, it’s impactful  not loud for the sake of volume, but like a storm breaking through carefully kept restraint. The intensity simmers just beneath the surface, and when it erupts, it commands the room. Jiro is somewhat of a fighter and a man’s man. He rarely ever shares his feelings and is usually the strong silent type.(Would prefer an Asian voice actor)