After years of oppression from the United Earth Sphere Alliance and OZ, a group of rebels in the space colonies send down five mobile suits made from Gundanium alloy known as "Gundams" to overthrow the militaristic regime. Of the five, Wing Gundam is intercepted by Lieutenant Zechs Merquise of OZ, and by sacrificing his Leo unit, he causes it to fall harmlessly into the Pacific Ocean near the JAP military point. The Wing Gundam's pilot, Heero Yuy, is found by Relena Darlian when he washes up on a shoreline. When he comes to, Relena tells him to stay calm since she had already called an ambulance. Instead, Heero attempts to use the self-detonation device built into his gundam through a control box on his flight suit, and when that fails, he hijacks the ambulance when it arrives, leaving Relena on the beach confused.
Elsewhere, Duo destroys a Leo manufacturing plant in North America, Trowa destroys the space port in Dover, Quatre takes out the scouts sent to investigate his space capsule landing in the middle east with the help of his Maganac Corp friends, and Wufei destroys an Alliance naval base in the Yangtze River in China.
Zechs then discusses with his copilot in his patrol craft the recent attacks by mobile suits similar to the one they encountered, and considers himself lucky for having survived such an attack. Then, back at the Saint Gabriel Institute, Relena is shocked when Heero enrolls and joins her class. After class, she decides to invite him to her birthday party coming up, but upon receiving the invitation, he rips it up in front her and all of the onlookers. Shocked, she begins to cry and ask why, for which he responds softly by saying, "I'll kill you".