It's the not-too-distant future, a time when internet technology has swept the world into the Network Age! Everyone carries around a portable communications deviced called a ""PET."" Each PET contains a unique personality program, or NetNavi, that freely navigates the CyberWorld. Lan, an enthusiastic 11-year-old, is introduced to his own, custom-build NetNavi, MegaMan. At first, Lan only wants to use MegaMan to play in cyber NetBattles against his friends' NetNavis. But when computer systems all over town begin to burst into flames, Lan and MegaMan team together to fight against a mysterious criminal syndicate that calls itself World Three!
