Mu

The Mu is an ancient culture within the MegaMan Star Force series. It was an ancient civilization on Earth, from which may have formed the Zerker, Ninja, and Saurian tribes. The empire eventually fell, and its last descendant is Solo.

The civilization of Mu plays a key role during the main storyline of MegaMan Star Force 2 and Shooting Star Rockman Tribe. It also plays a minor part in the story and bonus quest of MegaMan Star Force 3.

History
The history of the Mu is outlined in several symbols obtained while on the resurrected Mu Continent in MegaMan Star Force 2.

"There was a tribe of people with the power to see EM waves... the Mu." -Kath

"That special power of Mu was the object of fear from other peoples of the world, who sought to drive them out." -Fon

"Their search led them to Earth's End. And there they found the Great Being, the source of all EM waves." -Wol

"The Great Being first gave the Mu language." -Tuk

"The Mu used language to control EM waves and create prosperous civilization." -Zul

"The Mu people got their power to manipulate EM waves from the Great Being..." -Mir

"The Mu technology for materializing EM waves allowed their civilization to advance. And for a time, lived in peace..." -Ebesh

"One day Invaders appeared in the Mu's land, Earth's End, and tried to drive out the people of Mu." -Masa

"After the appearance of the invaders, the Mu were divided into those who embraced war and those who rejected it." -Foh

"Humans who rejected war, forsook their land and scattered across the Earth... And those who embraced war, used the power of EM waves to raise their land into the sky." -Fai

"Those Mu who left Earth used EM warriors to wipe out the Invaders." -Rai

"The Mu in the sky conquered all of the peoples on the ground and ruled the Earth..." -Chan

MegaMan Star Force 2
During the events of the second game, Dr. Vega attempts to restore the civilization of Mu by bringing it up from the sea and resurrecting Le Mu with the power of an OOPArt. She enlists the help of Hyde, Solo, Hollow, and several UMAs in order to bring her plans to fruition.

When Vega does eventually get her hands on an OOPArt from Geo Stelar, she attempts to use the reformed Mu Continent as a staging ground for starting the Neo Mu Empire. She sends out countless UMAs in order to test the people of earth by seeing who will not betray their friends. In the end, her plans fail, and Le Mu is defeated by MegaMan. Mu then crumbles and falls back into the ocean, taking the OOPArt with it.

MegaMan Star Force 3
Mu tech plays a very minor part during the events of the third game, as Rogue learns that it had been stolen and used in Dealer's Noise machinery. Interestingly enough, this results in Rogue saving MegaMan by accident when the Mu machinery he destroys had caught MegaMan in a death trap.

Just before MegaMan enters the Black Hole Server for the first time, he is stopped by Rogue, who was waiting for his chance to attack Sirius. Rogue explains that Sirius has a piece of Mu Metal, a substance from his civilization that he could use with Laplace in order to begin the resurrection of his civilization. However, the metal only emerged from Sirius once every few days and Planet FM would be destroyed by then. Unable to let that happen, MegaMan defeats both Rogue and Sirius and ends up absorbing the Mu Metal himself. Rogue accepts this, as it simply gives him another reason to kill MegaMan and an opportunity to get the metal back.

Trivia

 * Real mythologies about a civilization named Mu speak of both a continent lost in the ocean and theories that multiple civilizations were started by refugees of the Mu.
 * Mu and the OOPArts were mentioned by Dex Oyama and Mayl Sakurai respectively in the MegaMan NT Warrior manga while the class was in discussion about "Hyper Advanced Prehistoric Civilizations", however the class dismissed them as myth. It is possible that the Mu civilization was known about, but passed off as a myth.