Kei Kurono is the primary protagonist of the series. He is a reluctant hero and leader of the Tokyo Team. He has short brown hair and a lean body with an average height of a teenager. Kei bears a resemblance to Michael J. Fox; Oka has been quoted as saying that Back to the Future was a large influence on him as a youth. Throughout the first two arcs Kei is seen as a selfish, hesitant, and reckless person. However, his entire view on life changes after watching Kato's determination to keep everyone alive. After Kato and Kishimoto die during the fight against the Buddha aliens, he finds it in himself to overcome his fears and make Kato's mission a reality (To keep all of the players alive through the missions). As the missions go on, he is regarded as a "hero" and "leader" by the new members of the Tokyo Team. When he is cloned by Reika, his clone seems to develop the tendency to prove his abilities to himself, showing arrogance, recklessness, occasionally selfishness, and an almost self-rivalry. This has been proved as knowing he is a clone, and not really the real Kei. He attempts to accomplish a seemingly overpowering enemy by himself to prove he is not just a clone but as capable as the original Kei. However, he fails and is defeated, only to be saved by Reika at the cost of her life, resulting in self-loathing. This anger towards himself is most likely due to his psychological condition that he lost the fight, and not due to a lack of skills. His real self is also fairly confident after his many previous fights within Gantz. For example, when Eeva Gund challenges him, he promises Tae he will be back soon, even after witnessing Eeva annihilate an entire American team in a matter of seconds, despite their individual prowess. The clone loves Reika, despite his claim that he hates her for reviving him. He secretly loves her, seemingly more than Tae, as when she is revived, he declares his love for her and apologizes. After Reika is killed by the "Second Aliens", Kei charges recklessly at them in a rage, silently demanding they take him to Reika. He meets a swift end in his suicidal assault. The clone shows a great amount of care but also recklessness in this act. Kei is known to fight recklessly against the aliens, going up against the Rowdy and Grumpy Buddha aliens by himself, and against the Kappe Alien's Brachiosaurus. Originally, he fights so hard, just to survive. This is when he feels truly alive. Later he thinks of Tae during battle, determined to make it home again to see her. Izumi mentions once that no one should be able to do what Kei does and doesn't understand how he is so strong. Kei's enhanced strength and personality after the Dinosaur Mission mostly result from being together with Tae. Sometimes he is seen leading people, or going with someone. Other times he goes off on his own. As stated by many, Kei has an amazing ability, the ability to survive as he commonly finds a way out of situations many would consider impossible to escape alive, let alone unharmed. Kei seems to be more agile than most Gantz players, with several complimenting his speed when wearing the suit. He manages to keep up with, evade and even fight against Eeva Gund, who uses his speed to completely destroy a suited and skilled, American team. Eeva's motion is said to defy logic, and the fact that Kei can stand his ground and overpower Eeva without even getting so much as a scratch shows testament to his remarkable speed and skill. During their fight, Kei's figure appears as nothing more than a blur to untrained eyes as he maneuvers with incredible speed and attacks with his sword effortlessly. Kei also seems to be a quick thinker in the midst of combat, demonstrating the ability to find his enemies' vulnerable points, quicker than most. He shows excellent use in all of the Gantz equipment, favoring the various guns, while occasionally using the Katana in which he shows great proficiency using. Kei is skilled enough with the Gantz Sword to fight on par with and even injure the notoriously fast Eeva Gund, most likely the Katasrophe Aliens' greatest warrior This is a considerable feat, given the fact that Eeva doesn't seem to have been injured by anyone except from Kei. As a last resort he will use full frontal melee attacks, although nowhere near as well versed in martial arts skills like Kaze and a few other Gantz players, he can still hold his own against most foes and even uses the strength of the suit to surprise attackers, or use the suits strength in ingenious ways, such as punching his fist into the ground to prevent being blown away by the wind of a Buddha alien. His survival skills and desire to live and overcome the impossible has inspired many of his team mates, such as Suzuki, Kato and Reika to live and fight to the end. Despite his short time in Gantz he is easily able to overwhelm the more veteran players such as Nishi in a direct fight, and even score higher than players such as Izumi on a regular basis, showing a natural affinity for battle. Kei doesn't even need a suit to be able to attain the highest score, contributing to his knack for fighting the physically superior aliens and coming out on top. In fact, his survival instincts seem to come naturally as after having his memory wiped, he killed many would-be vampire assassins, by fashioning a UV light to shine at them and even outmaneuvering the physically superior vampires without a suit. Unlike the rest, he has the sense to take an x-gun home and test it out. In doing so, he figures out that the x-shotgun can lock onto multiple targets and fire at them all at once. He constantly shows the ability to improvise and see the bigger picture. He is very intuitive and is able to comprehend a majority of the Gantz equipment in a matter of moments after first use. He is also an excellent leader and has on several occasions shown excellent teamwork, especially so with his rival Izumi. Both of them are able to take down the so-called "Strongest Alien in Gantz", the boss of the Oni, despite said alien nearly killing his entire squad. In fact, he delivers the last few blows without the power of his suit. He has shown outstanding tactics for survival, telling people when to stick together, hide, and run in the utmost perfect timing to great success.