The scene begins in space, when Lieutenant Zechs Merquise is alerted by a suspicious figure on his ship's monitor. Still unknown to him, he sends three mobile suits (fighter mechas or machines) to fight the supposed enemy. The three mobile suits were surprisingly destroyed however and Lt. Zechs Merquise was compelled to face the enemy himself. His men ask him to use the mobile suit Aries which is a stronger mobile suit than the Leo he chose. But he won't be persuaded.

So begins the first duel with Gundam. This would not be the last battle. The Leo he used was outmatched against the enemy mobile suit he now knew as the Gundam mobile suit. Impressively of course, Zechs would still strike some furious blows but he would lose this time.

In the year 195 AC the Earth existed under one government, as one nation with its colonies in space. These "Space Colonial Stars" were also cities filled with people. OZ existed with enough power to control the Earth nation and the colonial stars, with the help of the Rockefeller financial institution funding its military, including the manufacture of mobile suits. But these colonies rebelled against OZ's control and employed five scientists to make five "Gundam," a mobile suit built with gundanium alloy. Five 15 year old Gundam fighters would pilot these and for now, be the colonies' champions.