Water Daimyō

He is the daimyo of the Land of Water.

Five Kage Summit Arc
During a meeting of the Five Great Shinobi Countries' daimyo he was cautious that the alliance would give shinobi too much power. This prompted the Earth Daimyo to suggest he didn't trust the ninja of his country. He eventually gave his consent to the formation of the alliance, albeit reluctantly.

Trivia

 * In the anime, Tenzen Daikoku was an aide to the Water Daimyo.