The story started between the war of the colonies and Earth, colonies was built when there are no more space on Earth to live on, thus creating peace talks between the colonies and Earth had been compromised and leaders has been assasinated each and every leaders of the colonies are being killed knock out of position this the group called OZ with the 5 scientist acknowledge each other and create a secret mission on Earth.
This mission is called Operation Meteor wherein five teenage pilots will undergo the mission and neither of them know each other, each one of them is given a mobile suit that each of the scientist built called "Gundams" this mobile suits are far more greater than the normal mobile suit that can be seen in the battlefield, because of the Gundanium alloy that can only be found on space they send this five Gundams on Earth to look for answers and retaliate against Earth.
Photo Taken From :http://image.123tagged.com/images/g/gundam_wing_characters-8822.jpg