Chisao

Chisao Oyama (大山チサオ) is a character from the MegaMan Battle Network series. He is Dex's young brother. He doesn't have a NetNavi. He speaks very childishly and believes that his brother is the best NetOp in the world.

MegaMan Battle Network 3
He appears in ACDC Town, looking for Dex arriving from Netopia. He runs away crying after Lan defeats Dex in a Netbattle. He later goes with the Lan's class to Yoka and visits the zoo. Chisao is then kidnapped by a condor and trapped on a high voltage tower. He is saved when all the animals return to normal.

MegaMan Battle Network 4
He appears shortly before the battle between Lan and Dex. He pretends to be kidnapped and makes Lan and MegaMan.EXE go all over the net looking for him. Chisao tries to make Lan late for the contest and miss his match.

MegaMan NT Warrior
He still idolizes Dex but he is a supposed genius and can operate GutsMan.EXE better than Dex and can perform the Program Advance. Chisao is tricked into believing that the curry shop run by the ex-WWW is a base for aliens and is given NoodleMan.EXE to destroy it but they convince them of their identities and all the conflicts are resolved in the end.