Chief

The police chief is an unnamed character appearing in the Yu-Gi-Oh! manga and first series anime.

Manga biography
The chief was investigating the Playing Card Bomber, who had been setting off a series of bombs in Domino City. While investigating, the chief would receive orders from the bomber to bring a Deck of playing cards, which would be necessary in controlling which bombs go off.

The chief goes to Domino Park after a bomb scare. He is contacted by the bomber, who tells him the bomb is in the ferris wheel. After hearing this, Yugi Mutou comes up to the chief, to tell him his friend Anzu Mazaki is on the ferris wheel. The bomber asks the chief if he's brought the usual Deck of cards and invites him to play a card game to find out which carriage it's in. The chief asks if there is anyone good at card games, who can help in. Yugi switchs to Dark Yugi and volunteers. After playing a game of "Clock Solitaire" as requested, Yugi was able to stop the bomber and report his location to the chief.

The Evil Gamer - The Trap of Hell
The chief goes to Burger World, where he has tracked an escaped convict. He alerts the staff, Anzu, Miho, Honda and another, that the escaped convict might be in this restaurant. Yugi and Jonouchi listen in too. He shows them a picture of Tetsu Tasaki, thinking that's the convict, but also points out that the convict is a master of disguise and its rare to see him out of disguise.

The chief tells them that after stealing the jewels, that convict struggled with a guard, so he may have a mark on his right calf. Anzu spills over a basket of toy cars, so they can search customers' legs for the scar. After one customer makes a fuss over this, the chief is forced to alert the customers of the convict.

None of the customers were willing to co-operate, so the chief tells the gang that the culprit has an allergic reaction to eggs. Anzu lies about the burger buns containing egg out loud, causing Tetsu Tasaki to panic and expose himself.

The chief tries to subdue Tasaki before he can escape, but in his struggle Tasaki knocks over one of the staff, revealing him to be the true convict, Jiro the Yellow Spider.

Jiro takes a gun, preventing the chief from arresting either man, until Dark Yugi defeated Jiro in a Shadow Game.

In a Bomb Game - The Worst Date
The chief is sent to Domino Park after a bomb scare. The bomber phones him to say that the bomb is in the ferris wheel and invites him to play a game involving balloons to find save the hostages in the carriages.

The chief receives help from Dark Yugi. After playing the game, Dark Yugi inflicts a Penalty Game on the bomber, making him go berserk and fall out of his carriage allowing him to be arrested.