Mega Man Battle Network (series)

In the year 200X, the internet has become integrated with every piece of electronic equipment in existence (from TVs to ovens), and people carry around hand-held devices known as a Personal Exploration Terminal (PET). These devices act as phones, pagers, instant messengers, news beams, and hacking devices all rolled into one. Additionally they are able to be customized with a “NetNavi” or a human-like personality that can be anything the owner desires.

A fifth-grader named Lan Hikari(光熱斗, Netto Hikari in Japan) has a NetNavi named MegaMan.EXE (Rockman.EXE), a virus-fighting blue-suited cyber personality who is also Lan’s best friend. Although MegaMan.EXE has no body (unless the PET device itself counts), he can wander around in Cyberspace and explore computer systems as if they were alternate worlds. Together Lan and MegaMan.EXE (also known as just MegaMan) cooperate to fight off hackers and viruses.

MegaMan Battle Network
The relative peace of Lan’s hometown is shattered when electronic devices begin mysteriously going berserk. Talk of a takeover by the “World Three” (“WWW”) is abound. MegaMan and Lan decide to tackle the problem from two sides—the real world and cyberspace. It’s going to take everything they have to counter the mastermind behind all of this...
 * Main Article: MegaMan Battle Network
 * Also known as Battle Network Rockman EXE

Mega Man Network Transmission
Taking place a month after Mega Man Battle Network, Lan and MegaMan.EXE try to track down the mysterious and destructive "Zero Virus" that infects Navis and causes mayhem via PET e-mail.
 * Main Article: Mega Man Network Transmission
 * Also known as Rockman EXE Transmission

MegaMan Battle Network 2
Peace has been broken again, but the culprit is not WWW, it's Gospel. With a plot to create a Super Navi and destroy the Net, can Gospel be defeated before it reaches its goal? This game gives us Style Change, an all-new power affecting MegaMan's abilities, and a slight revamp to the folder building system.
 * Main Article: MegaMan Battle Network 2
 * Known as Battle Network RockMan EXE 2

MegaMan Battle Network 3 White and Blue
WWW is back, with a more devious plot. The Leader plants to control Alpha using the Tetra Codes and the Alpha Code. With several incidents occurring, ranging from animals in the zoo going berserk to a phony tournament, can MegaMan prevent the WWW from laying its hands on the Codes before it's too late? And just who is this Super Navi who has come to seek vengeance? This game gives us the Navi Customizer, along with revamping of folder design mechanics.
 * Main Article: MegaMan Battle Network 3
 * Known as Battle Network Rockman EXE 3 and Battle Network Rockman EXE 3 Black

MegaMan Battle Network 4 Red Sun and Blue Moon
In the year 200X, a meteorite has appeared, threatening the destruction of the earth. To save the earth, a tournament has been set up in hopes of finding the best Net Battler in the world. However, ShadeMan.EXE and LaserMan.EXE intervene with an alluring power that threatens the Navi's very own soul... Can MegaMan resist the temptation of the dark power? This game introduces Double Souls and Dark Chips.
 * Main Article: MegaMan Battle Network 4
 * Known as Battle Network Rockman EXE 4 Red Sun and Blue Moon

Rockman EXE 4.5 Real Operation
Choose your NetNavi and Go! Play minigames. Taste new NetNavis. This game introduces a new way of battling, where the Navi is on autopilot and can attack on their own, as if in the anime.
 * This game was never released in US

MegaMan Battle Network 5 Double Team DS, Team ProtoMan, Team Colonel
Nebula has seized control of several areas of the Net, intending to spread its dark influence again, and it's up to MegaMan to free the Net from its grasp. However, he cannot do this by himself, instead, he must learn to work with certain former foes and rivals in order to achieve this. This game features new Dark Chips, Chaos Unisons and Liberation Missions, along with the Party Customizer in the DS version.
 * Main Article: MegaMan Battle Network 5
 * Known as Rockman EXE 5 DS: Twin Leaders, Rockman EXE 5: Team of Blues,Rockman EXE 5: Team of Colonel

MegaMan Battle Network 6 Cybeast Falzar, Cybeast Gregar
In the year 200X, Lan and his family moves to Central City and he has a new school, but WWW is back and tries to capture the Cybeasts that sleep within the Net, Gregar and Falzar. This game introduces the Cross System, Beast Out and Beast Over, along with a few revamps of existing systems. And you can meet Boktai if it's the japanese version! =D
 * Main Article: MegaMan Battle Network 6
 * Known as Rockman EXE 6: Dennoujuu Faltzer and Dennoujuu Grega

Trivia

 * MegaMan Battle Network follows a similar timeline to the original-X-Zero-ZX-Legends series, but places a possible alternate reality if Internet expansion had been chosen over robot expansion on the Battle Network-Star Force timeline instead of vice versa in the original timeline.