During the One Year War in Universal Century 0079, the Earth Federation and Principality of Zeon engaged in a fierce conflict in the Thunderbolt Sector, notorious for its electric surges. As Federation pilot, Io Fleming, led a charge against Zeon's ace, Daryl Lorenz, the sector became a deadly battlefield. Both sides had highly skilled soldiers and refused to back down as they strategically fought amidst the debris of destroyed colonies. Io, now equipped with a powerful prototype Gundam, became an even greater threat to Daryl and his unit. However, in order to ensure a Zeon victory and crush his enemy, Daryl knew he must make a sacrifice to obtain more power. Failure would mean watching his comrades fall to the hands of a single man.