The series is set in the year 200X, (sometimes written as 20XX) in an alternate version of the original Mega Man universe in which networks, rather than robots, were the subject of the most research. Like the original, there were two main projects and only one was funded, but unlike the original, the work of Dr. Tadashi Hikari (the series' version of Dr. Light - the name makes reference to both "Light" and "Right" being correct names for Mega Man's creator in the original series) in the field of networking and AI programs had been funded over Dr. Wily's research in robotics. The result of Dr. Hikari's research was the PET (PErsonal Terminal, pronounced P-E-T rather than the word "pet"), a small computer which is used similarly to a cellular phone or PDA and which contains a customizable artificial intelligence complete with emotions, known as a NetNavi (short for Network Navigator). A NetNavi is responsible for helping the operator search, use, and surf the internet as well as protect the PET and itself from viruses. Within years the Internet evolves to the point where it literally becomes possible to send an AI into it and physically move around as if it were another world, and technically, it is. There is some danger, however: viruses evolve alongside Navis and the Internet to become intelligent on some level. Navis presumably have advanced data to prevent tampering with their code directly: Viruses cannot harm them by corrupting their data, unlike viruses of our age, who cannot do anything but this. However, because the Internet has evolved to the point of taking on a manifestation, so, too, can virtual weapons be used. If a Navi or a Virus takes too much damage, its programming will lose integrity, disperse, and be deleted shortly afterwards. Each Navi has antiviral weapons that are built directly into its programming that provide basic defense, and can, in addition to this, be sent weapon programs from the PET via the use of BattleChips.
Some years later, the series focuses on Tadashi's grandson, Lan Hikari (Netto Hikari [1] in the Japanese version), both original and English names being a play on computer terminology ("Netto" is a pun on "Internet", while Lan is a pun on LAN), and his extraordinary navi, MegaMan.EXE (Rockman.EXE). They somehow get involved in foiling the schemes of a net-crime organization called the WWW ("World Three"), headed by Wily.
In another tribute to the original series, most (but not all) of the Navis in the series are named after characters from the original series (although in Battle Network all NetNavis are supposed to carry the "EXE" file extension, to differentiate them from their original counterparts). As the games progressed, however, certain characters from the X series, most notably Zero, Iris and Colonel have also appeared as NetNavis, prompting some fans to believe that, similar to the original series, the Battle Network series will eventually transition to an 'X' stage. Completely original NetNavis have also been made for the series, with some exclusive to the anime series. In every game since the second (with the exception of Battle Network 3), NetNavis used by Mr. Famous were created by fans of the series, being winners of design contests from Capcom of Japan.
