Dex Oyama

Dex Oyama, known as Dekao Oyama (大山デカオ) in Japan and Dex Ogreon in English anime and manga, is a character from the MegaMan Battle Network series. He is the rival of Lan and operator of GutsMan.EXE. He has a brother called Chisao. He believes that Dex is the best NetOp in the world and Dex tries desperately to maintain his respect. In the games, he and GutsMan can be fought in every game up to MegaMan Battle Network 4 for his chips.

MegaMan NT Warrior
Dex is Lan's rival, like in the games and always defeats Lan in Netbattles but after Lan's generic NetNavi is upgraded to MegaMan.EXE, he is easily defeated. Dex provides comic relief in many episodes. Once, he was taken to the hospital because a cat bit his leg and wouldn't come off. He also has a crush on Mayl but is always turned down.

In MegaMan NT Warrior Axess, he goes to another country with the ex-WWW members to work at their curry shop and train hard. When he comes back, he has a gung ho attitude and challenges Lan and MegaMan to a Netbattle. However, they are attacked by BurnerMan.EXE and MegaMan teams up with GutsMan to defeat him.