The year is 200X. Rapid growth of internet technology has given rise to Network Society. People carry with them PETs, mobile devices equipped with sentient programs called NetNavis, which they use in order to enjoy the many benefits the network provides. But even though the network has improved their way of life it has also brought with it new outlets for cybercrime. The protagonist, Lan Hikari, and his NetNavi, MegaMan.EXE, must work together to solve numerous incidents.