|Name (Romaji)||Washizu Iwao|
|Voiced By||Masane Tsukayama (津嘉山正種)|
Iwao Washizu (鷲巣巌, Washizu Iwao) is an old man who has made hundreds of billions of yen and become one of the most powerful people in the underground world. After building up massive funds from shady dealings in Japan's post-war era, he used the money to tempt people─especially young ones─to bet their lives for the chance to win large sums of money. He enjoys doing this, so a match between Akagi and Washizu was arranged. Washizu and Akagi play mahjong in an unusual way, which Washizu calls Washizu Mahjong. In Washizu Mahjong, glass tiles replace most of the tiles, making a large portion of each player's hand visible to the other players.
A spin-off, Washizu: Enma no Tohai, depicting Washizu in the pre and early post-war period, began serialization in Kindai Majan in 2008.
Washizu has long white hair and a long crooked nose. His facial expressions often become very exaggerated when he is winning or losing.