He has short brown hair and is the average height of a teenage boy.
Like the person he was cloned from, Kei Kurono, Kei is brave, caring and relentless, never failing to try and do the right thing, and to fight for the people important to him. Kei is torn by his love for Tae and attraction and resentment towards Reika for creating him.
Kei was born out of the obsessive love Reika held for Kei Kurono. After being rejected by Kurono, who was in love with Kojima Tae, Reika seized an opportunity to "revive" Kurono from the Gantz memory, creating a second Kurono.
Kei is created after the conclusion of the Italian Mission. Reika accumulates 100 points and initially plans to resurrect Suzuki, but Gantz seemingly malfunctions, and Suzuki is not resurrected. After the team leaves the apartment, Reika returns, having forgotten her clothes, and encounters the man inside the Gantz ball. He asks her who she wants to resurrect and Reika decides to seize this opportunity to create a Kurono of her own. Kei initially vehemently rejects Reika, declaring that he is still in love with Tae, and that she is insane.
Kei rushes home, only to encounter his original self planning to call Tae. Realizing that there is no place for him there, he returns to Reika's apartment. He spends the night on her couch, and in his rage, attempts to rape her. After she gives her consent, however, Kei merely apologizes and goes back to sleep. Later, Kei seeks out his original self, who nonchalantly states that there is no problem. He (the original) will stay with Tae, and Kei (the clone) will be free to be with Reika, thus "everyone will be happy." Kei resigns himself to his fate, and goes to live with Reika. Reika goes so far as to quit her job in order to be with Kurono, and asks him to marry her. He declines, stating he is only 17 and not legally allowed to marry.
When the Giant Aliens invade Earth, Kei and Reika fight them, with the assistance of several other Gantz hunters. Kei and Reika, along with Kato, Kaze and Sakurai are forcibly conscripted by Zaibatsu executives who have hijacked several Gantz balls to a reconnaissance mission aboard the giant ship. The team meets with heavy casualties, and are eventually transported out again.
United Rescue Arc
After the mission, Kei, Reika, Kato, Kaze and Takeshi head to the Gantz room in hopes of answers and a way to fight the invasion. There, they find the man operating Gantz and Nishi. Gantz offers to help them in any way possible, and Kei asks if he can possibly make contact with other Gantz balls. Gantz helps him transmit a message, asking for volunteers to undertake a rescue mission aboard the ship. They plan to use intel from the American Gantz team in an attempt to save as many captured humans as possible.
The new team manages to rescue many humans, but their progress is hindered when Gantz is hacked, and they are transferred to somewhere in the Giant city. Here, they encounter vicious insectoid aliens, which kill one of their members. The team takes out most of them, leaving only one large monster. Kei volunteers to stay behind, declaring that unless the monster is dealt with now, it would come back and kill them all later. Part of his motivation for remaining behind, however, is proving that he is as good as the other Kurono. Reika refuses to leave Kei, returning despite Kei and the rest of the team's wishes. She arrives just in time to save Kei, but he angrily tells her to go away, and that he wishes he could see Tae one more time.
Kei is knocked out in the battle, leaving Reika to fight the monster alone. As Kei gains consciousness, he sees the creature dead, and finds Reika dead as well. Maddened with grief, Kei desperately attempts to resuscitate her, weeping all the while as he realizes that he does love her after all, regretting the harsh words he had spoken to her before her death. Realizing that she is gone, he takes her body to the rest of the team to be cremated.
The Final Challenge
With the Giants all but defeated, Kei and the remaining rescue team are taken to a "room of truth" where they encounter the God Aliens. These aliens reveal that they sent the Gantz technology to Earth as a means of protecting them against alien invasions. The aliens go on to show their disdain for humanity and declare humans to be nothing more than "things." Kei angrily objects, and to prove their point, the aliens resurrect Suzuki, Sakuraoka, Kishimoto, and Reika. Just as Kei gets a chance to reacquaint himself with his lost loved ones, and to finally tell Reika that he loves her, the aliens kill all four of them again. Maddened with grief and rage, Kei tries to lash out at them, but is killed as well. Kato attempts to avenge his friend, but is held back by the rest of the team.
The aliens state that Reika will be reborn in two years as an American woman, and that Kei will be reborn twenty years later as her son.
Abilities & Skills
Like the real Kurono, Kei is an extremely skilled Gantz fighter. He is competent in the use of almost every weapon available to him, including the X, Y, and Z-Guns, the sword and the chopper.