Shu Ouma was a normal Japanese teenager living in an occupied Japan controlled by GHQ after an outbreak of a devastating disease known as the Apocalypse virus, until he meets a girl named Inori Yuzuriha, who tells him to deliver a package to a man named Gai Tsutsugami. It turns out that Gai is the leader of a resistance group called the Undertakers, who is seeking the package, as it contains as "genomic weapon". In the process, Shu comes in contact with contents of the package, gaining what those with knowledge of the genomic weapon call the "Power of the King", the power to draw tools and weapons, called voids, from anyone under 17. Shu and the resistance are attacked by GHQ again shortly later. Shu runs into Inori again, who tells him to "use her". Shu draws her void, a sword that gives him superhuman speed and strength and automatically puts up shields capable of blocking missiles. Shu using the sword to slice the leg off a GHQ mech, destroying it. Shu is recruited into the "Undertakers" by Gai, and is sent on missions to rescue a captured agent and later, to sabotage and orbital laser sattellite facility. In these missions, Shu discovers some of the voids others possess. Among them a mirror that can reflect laser weapons and an anti-gravity gun. Shu also discovers he can combine the gravity gun and Inori's sword to create a powerful laser weapon, which he uses to shoot down an orbital laser satellite. Shu's career in the Undertakers culminates in an attack of GHQ HQ, where Shu learns a rogue GHQ faction has taken over, can plans to use the original victim of the Apocalypse Virus, Shu's own sister, Mana to spread the virus. Mana and Gai are apparently killed in the fight, and Shu escapes, along with to female Undertaker operators named Ayase and Tsugumi, to hide out in his old high school.
During this period of time, the area around the high school is quarantined, and the students quickly discover that GHQ has created a "kill zone" around the perimeter of the quarantine zone, into which automated drones guarding the base will kill anyone who enters, attempting to escape. Shu is made the student council president and de-facto leader after the previous president, a (presumably half-Japanese, judging from her name) girl named Alisa Kuhouin, failed to act in response to the crisis. Shu and several other student leave the school to find more vaccine for the Apocalypse virus, however, and, in the process, one of the Shu's friends, a girl named Haré Menjou is killed by a GHQ attack helicopter. After Haré's death, Shu becomes a dictator of sorts of school, and implements a ranking system based on the utility of their voids, with S as the best and F the worst. While S and A-ranked voids get better treatment, including more food and Apocalypse virus vaccine, and those with void weapons often working as part of Shu's "secret service", his bodyguard and secret police. Those with F-ranked voids are forced to live in tents outside the school, are given less vaccine, meaning many of them, including one of Shu's old friend's, Souta, develop early-level symptoms. Nonetheless, the F-ranks are forced to locate conventional weapons in an abandoned military ship docked near the school, in order to prepare for Shu's coming plan. Discontent of Shu's rule grows, incited by Arisa and an ex-undertaker known as "Argo". Shu manages to complete his plant to use his voids to sabotage the drone control node at Tokyo Tower, and escape, several students are killed in process. As the last students leave the quarantine zone, Shu is accosted by a large group of low-rank students armed with MP5 Submachine Guns, AK-47s, and other conventional firearms. Souta sneaks up on Shu and pushes him into a crater. However, before the rebels can execute Shu, four GHQ mechs arrive, forcing them to flee. The vehicles are accompanied by Gai Tsutugami, who states that Shu thinks himself as king, but that he is merely a usurper. Gai then cuts off Shu's right arm with Inori's void sword, stealing his powers.
After losing his powers Shu escapes and hides out with another group of ex-Undertakers, and, Gai kidnaps Inori and takes her GHQ headquarters. After a GHQ attack, Shu gets a hold of another "void genome", and uses it, drawing out his own void, which takes the form of a cystalline right arm replacing the one Gai severed. Shu used the voids of his friends to fight off GHQ, but, in the process, his void heals Souta's Apocalypse virus, but it is transferred to Shu himself. Shu and the others discover the intentions of GHQ form Shu's stepmother, Haruka, who works for GHQ along with Shu's father. They learn Mana is, like Gai, still alive, in fact, Inori is a secondary personality of Mana, and Gai Shu's father is part of a ancient secret society known as Da'at, which plans to revert Inori to the Mana personality and Mana's abilities as the original infected to kill off the entire world except of Gai and Mana using the Apocalypse virus so Gai and Mana can be come the "Adam and Eve" of a new, superior human race. Shu and his allies attack the GHQ headquarters, Shu defeated a mysterious man claiming the be leader of Da'at and then killing Gai himself. Shu survives the battle with Gai, although Inori sacrifices herself to stop Mana.
Battle vs. Saito Hiraga (by SPARTAN 119)Edit
Tennozu High School, AU where Saito returns from Halkegnia to the Guilty Crown Universe
Saito Hiraga burst into the student council office of Tennozu Academy, which had been turned into the office of Shu Ouma, self promoted student council president turned dictator of the group of students surviving in Tennozu Academy.
Saito knocked the two "Secret Service" guards unconcious with the side of his sword, Derflinger, before confronting Shu and Inori Yuzuriha.
"You think you can just turn people into second-class citizens based on their utility to you?! You think you can simply deny them adequate vaccination against the virus!?", Saito asked.
"I am doing this to save school. In order to save us all, sacrifices must be made.", Shu replied, "You would never understand, you, with your high and mighty ideals... My plan is the only plan that will work. Any one who opposed me is a threat the survivor of everyone in the school.. A threat that must be... eliminated!"
Shu drew the void sword out of Inori and swung it at Saito, who blocked with Derflinger. Furiously, Shu attempted the thrust his longer weapon at Saito, who sidestepped the blow.
Saito could not melee attack Shu with his longer weapon, so he drew his SiG Sauer P220 and fired three shots at Shu. Shu brought up a round shield of blue light using the powers of the sword.
Tried to slash at Saito, but in so doing, dropped the shield and was struck in the arm with a round from Saito's SiG. Shu swung his weapon furiously, slicing through the wall and falling forward, out of the school building.
As he fell, Shu drew the gravity gun, which he had drawn from Kenji Kido earlier, and fired decelerating his fall and landing safely on the ground. Shu combined the gravity gun with Inori's sword, creating the massive laser cannon. Shu fired, sending half of the school building up in a ball of flames as the laser continued into the sky.
Shu was sure Saito had to be dead... but he was not... The was made plainly clear enough when an M72 LAW rocket impacted Shu's laser cannon, blowing it apart.
Shu stared in shock. He had survived the impact, but both voids that made up the cannon were destroyed. Shu knew what the meant... Inori and Kenji were dead.. He didn't really know Kenji well.. but Inori..
Shu shouted in furious rage, drawing an MP5K and firing wildly, forcing Saito to take cover behind a pile of debris to get out his AK-47. Saito returned fire, hitting Shu in the left arm. In his infuriated state, however, Shu seemed not the notice as he fired a hail of lead, chasing Saito out, into the parking lot of the school.
There, little did Shu know, Saito had gotten a hold of the Flak 88 that was transported back to its original world after spending almost a century in Halkegnia (remember, GC takes place in 2039). The gun was now set up by a group of students with "F-ranked voids" that Saito was aiding in their rebellion.
Shu walked into the parking lot and took aim at Saito and his allies manning the Flak 88.
"Give it up", Saito said.
Fired a burst from his MP5 missing.
"Fire!", Saito yelled.
The Flak 88 roared as one of the "rebels" pulled the lanyard, firing off shell. The shell impacted right where Shu was, vaporizing his body in the blast.
WINNER: Saito Hiraga
Saito Hiraga won this match for a few different reasons. First of all, Saito's "rune of Gandalfr" allowed him to use any weapon with the skill of an expert. Secondly, all of Saito's weapons were always on hand, whereas Shu had to draw his weapons from another person. Finally, while Shu had some formal firearms training, he relied to much on his "Power of the King", meaning he is a rather poor shot.