Shu Ouma

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.