Somewhere in Tokyo, there is a room. In that room is a black sphere. Periodically, people who should otherwise have died are transferred to the room. There, the sphere gives them special suits and weapons, and sends them out on a mission to kill aliens here on Earth. While these missions take place, the rest of the world is largely oblivious to them. These missions are lethal - few participants survive them. The sphere calls the shots, and it`s not the slightest bit nice. It`s name... Gantz
By Hiroya Oku (Gantz)
Voiced by: Daisuke Namikawa (Japanese), Christopher Ayres (English)
Kei Kurono is the main protagonist of Phase 1. Kei is 10th grader who is summoned by Gantz, along with Masaru Kato, after being hit by a subway train in an effort to help a hobo who passes out on the tracks. In the beginning, he is a rather selfish character who often ended up being the reluctant hero. However, after seeing Masaru sacrificing his life trying to save him in the first mission, Kei starts taking care of other people as well he starts to to avoid anyone to die. During missions, Kei remembers several moments in which he was brave than then and try to fight the aliens using his child movements. After reviving some of his former friends, Kei leaves the game due to a request from his comrades. His memories of the Gantz "missions" are supposedly erased, but he begins to remember them through hints and traces in life. The vampires group search for Kei and kill him since he has killed several aliens. However, during Phase 2 Kato becomes dedicated to revive him. After Nurarihyon is killed, he is revived by Masaru Kato.
Voiced by: Masashi Oosato (Japanese), Illich Guardiola (English)
Masaru Kato is summoned, along with Kurono, by Gantz after they were hit by a subway train while helping an unconscious hobo who fell on the tracks. He is an old friend of Kurono and serves as a secondary protagonist until his death and as the main protagonist in phase 2. At school, he acts as a guardian to the weaker students who often find themselves bullied, getting himself a bit of a reputation for fighting. He is killed during the Buddha mission but revived months later.
Voiced by: Hitomi Nabatame (Japanese), Shannon Emerick (English)
Kei Kishimoto first appears naked in the Apartment as her death involved slitting her wrists while in a bathtub. Unlike many of the characters of the series, she did not exactly die. Gantz slipped up, accidentally creating a copy of herself to use in missions while her original self survived. Kurono has a deep crush on her, but she herself has a crush on Masaru Kato. It is hinted that she has a crush on Kurono in the manga. Gantz calls her by the names "Boiled eggs", "Titz" and "Miss Melons" (in the original Japanese: "Kyonyu" ("huge breasts") due to her fairly large breasts. She dies during the Buddha mission.
Shion Izumi once participated in Gantz's missions, achieved 100 points, and left the game with his memories erased. Since then, he began to remember the excitement of the missions. He committed a mass shooting on a busy street disguised as a black man, killing 387 before being stopped by Kurono, in an effort to return to Gantz, which he succeeded. Izumi possessed tremendous fighting skills and, aside from Kei Kurono, proved stronger than any other member on the team. He showed very little regard to ethics and cared only about the missions and reaching the goals. He was killed by the vampires near the end of Phase 1.
Voiced by: Masashi Yabe (Japanese), Chris Patton (English)
Joichiro Nishi (Nishi Jouichirou) is a middle-school veteran of the Gantz world, having arrived there over a year before the beginning of the Gantz. While running away from police officers after shoplifting, he fled onto an apartment building roof where he fell to his death. Much like how Kurono started out, he is also selfish and has a Social Darwinist approach to life. Nishi is reluctant to reveal anything about the Gantz or himself, but he runs a web site where he posts information about it (carefully avoiding Gantz's rule about informing outsiders, which would in turn prove fatal). Gantz calls him "Mr. Nishi," which is rather interesting given how informally or derisively he refers to most of the other participants. Nishi is killed at the beginning of the Tanaka / Suzuki Alien mission, but after six months of existing only inside Gantz's memory banks, he is revived by Kaze at Kurono's request following the end of the Oni mission. Ostensibly, Kurono hopes that Nishi will be able to provide information about Gantz to the game players. Whether or not Nishi actually provides any information or if this information has proven useful is yet to be seen. It seems that Nishi and Izumi have a past relationship as "teammates" before Izumi's memory was wiped and he won freedom. It has not been revealed if Nishi and Izumi were friends or just acquaintances forced to fight Aliens together by Gantz. It is revealed that Nishi got 75 points after Nurarihyon was killed, presumably from killing the Tengu alien.
Yoshikazu Suzuki, best known as "Old Man"*. Not much is known about him except that he is a fairly old widower who has a grandson. Surprisingly, it does not take long for Kurono to grow attached to him and vice versa. He sees Kurono as a role model, and even gives his 100 points to revive his friend Masaru Kato so that Kei may leave the game. He sees Kurono as the world's hope for "survival". He has saved Kei's life multiple times and he emulates Kei. After Kei dies however, it seems as if his morale lowers and he sides with the majority on not trying to help others because it was too dangerous. In the battle of Nurarihyon both of his arms are lost.
* The character's nickname in Japanese, "occhan", is not as rude-sounding in Japanese as "Old Man", and may have been better translated to something like "gramps".
Hiroto Sakurai is a psychic who receives instructions on how to unlock his latent powers from Sakata after attempting suicide. He is then encouraged by Sakata to kill his bullies who sexually abused him with the use of his powers, which he does. However, he later regrets it, realizing how it feels to be a murderer. When he and Sakata witness Izumi's Shinjuku massacre, he insists in trying to stop Izumi and convinces Sakata to join him, arguing that it is a good opportunity to redeem themselves for the murders they committed themselves. While they do put up a good fight, Izumi still does manage to kill both, leading them to Gantz.
A phenomenal learner, he masters his abilities rather quickly. He dies in the fight against the Flame Oni, but is revived by Sakata. Gantz calls him "Cherry", taken from the Japanese Sakura and which is his online handle. He has a girlfriend named Tonkotsu who he first met after he murdered the people who abused him. He is also somewhat conflicted with Sakata's comments to Kato about not reviving others, since after all Sakurai himself was recently revived by Sakata.
Kenzo Sakata (Sakata Kenzou) is another psychic. He teaches Hiroto Sakurai to use his latent psychic powers, thus Sakurai refers to him as "master". He and Sakurai die while trying to stop Izumi's massacre in Shinjuku, leading to his arrival to Gantz. He seems to have an unorthodox view on people's lives; he tells Sakurai that he was like him once and that he himself has killed, and encourages his pupil to kill those bullying him. Gantz calls him "Stupid Newb" and "Dumbass". His psychic powers are significantly reduced, and a recent medical examination indicates that continued use of his powers has significantly aged his internal organs. After the Oni mission he uses his 100 points to revive Sakurai. In the Osaka mission however, he says that they should forget about the death and that by bringing them back it "cheapens" their lives. He was killed in the battle of Nurarihyon by holding off the 100-point alien while the rest of the Tokyo team escapes. He tells Sakurai not to bring him back no matter what. He has never been seen without his sunglasses.
Reika is a beautiful, young and popular idol. Like almost everyone else, she is caught in the line of fire during Izumi's killing spree in Shinjuku. She develops a crush on Kurono after seeing him in action during her first night as a participant in the game (the Dinosaur Mission). Gantz used to call her "Kurono's #1 Fan," but now he just calls her "Reika." Surprisingly enough, she proves to be a formidable opponent against the Aliens. She uses her points to resurrect Tae because she wants Kurono to be happy. It is not until Kurono chooses to be free that she confesses to him that she loves him. After Kurono departes from the game, she is appointed the new team leader of Gantz. She receives a phone call from Kurono just before he is attacked by the vampires, but does not arrive in time to save his life; she even tries to hold on to Kurono's body in order to be transferred with him in the hope of reviving him. However, this is stopped by one of the vampires who uses her body to transfer to the Gantz room instead. Like Kato, she is deciding whether or not to revive Kei, because he will neither remember her nor return her feelings of love.
Daizaemon Kaze (Kaze Daizaemon) is a tall and incredibly powerful martial artist who comes from the countryside to Tokyo looking for a good fight. He first meets Gantz after the Shinjuku massacre, where he makes a valiant yet doomed attempt at stopping Izumi. He seems to care about Takeshi, a young child who admires Kaze as his "Muscle Rider" savior. Gantz calls him "Countryside General," ("inakappe daisho" / "General Bumpkin") and later on "Muscle Rider." After the Oni Aliens mission he collects slightly over 100 points, but chooses to remain in the Gantz game in order to both continue testing his strength and fighting skills against more powerful enemies and to protect Takeshi. So instead of being freed he chooses to revive another person, settling on Nishi after asking for Kurono's suggestion. Despite his cold outlook, he does have a softer side—in fact, he weeps when he thinks of how Takeshi died at such a young age without ever having experienced love. He also takes some sport in the game, though nowhere near as much as Izumi. He is the only team member who doesn't use weapons, relying on nothing but the Gantz Suit which amplifies his already incredible strength.
Kouki Inaba is an ordinary Joe, gunned down in the Shinjuku massacre. He is the only participant apart from Izumi that does not train with Kurono as he thinks Kurono should not be leader. He even sides with Izumi during the Tae Alien mission to assassinate Tae. Eventually, he realizes his only chance of survival is under Kurono's guidance. And at the end of the Oni mission, he gives Kurono his support. He is quite the coward when it comes to fighting, and tries to feign a cool head in these situations. It is hinted at numerous occasions that he is attracted to Reika, and he has admitted the fact to an Oni Alien he thought was Reika, subsequently having sex with the alien. After the Oni mission, he witnesses Kurono's brave attempts to fight the ultimate boss in the Oni Mission. He gains respect for Kurono and believes that Kurono could actually become the group leader. Despite the fact that Kurono dies, he still participates with the other Gantz team members in fighting the aliens. In the battle of Nurarihyon he tries to escape the 100-point alien, but ends up losing both his arms and a leg.
Takeshi is a young boy of toddler's age who dies due to parental abuse (his mother's boyfriend beats him to death for eating his pudding). He draws a fictional hero called "Muscle Rider" before his death, and when he awakes inside Gantz's room as a participant in the game he believes that Kaze is his "Muscle Rider". To no one's surprise, he still does. By chapter 240, he discovers and uses the abilities of the suit, this includes the utilization of the "back attack", which happens to be Kaze's signature move. Despite Takeshi's small size, he is more than capable of defending himself against average opponents. Having imitated Kaze's fighting style to a "T", Takeshi manages to dispel a group of monsters that surround him, as well as injure a rather large and hideous creature that comes from the river. During the battle with Nurarihyon, Takeshi was seriously injured by a spray of pods that emerged from Nurarihyon's body during one of his many regenerative phases.
The Osaka Gantz Team
The most recent mission brought the Gantz team into contact with their Osaka-based counterparts. Members include Shimaki (nicknamed "George"), Muroya Nobuo ("Nobu"), Kuwabara Kazuo, Taira Sanpei, Hara Tetsuo, Kimura Susumu, Nakayami Miho, Yamada Sumiko, Hanaki Kyou ("Kyou"), Oka Hachirou and Yamasaki Anzu.
The Osaka Team is, in essence, a gang of rebels: unlike the Tokyo team, they have appointed no leader, nor do they have any attack plans. Often, an Osakan team member will choose an enemy to fight solo while the others stand by, not assisting even if that team member dies. Several team members play with their prey instead of focusing on exterminating all targets; three members are dubbed "3-S" for being extremely sadistic. Kuwabara Kazuo rapes the female aliens before killing them. Most of the Osakan team members are highly confident in their abilities, having obtained 100 points at least once. Oka Hachirou, for example, is said to have obtained 100 points 7 times. Because of their overconfidence, most of them were killed during the Nurarihyon mission. As of chapter 277, the survivors are Kuwabara Kazuo, Muroya Nobuo, the bespectacled 17-year-old virgin, and the two groupies.