Take on the world's toughest NetBattlers and save the planet from an asteroid while you're at it in Mega Man Battle Network 4: Red Sun or Blue Moon. Lan, a school kid, does the walking while his computer program, Mega Man.exe, does the virus stompin'. The Web is buzzing with news of the big Den Battle Tournament. It's the ultimate battle between Navis (electronic personifications on the Net). Lan and his Navi, Mega Man, must find a way to get into that tournament.