|Debut||0001. An Incident|
|(Current) Final Appearance||ongoing|
|Voice Actor||Illich Guardiola|
|Live action actor||Matsuyama Kenichi|
|Current Status||Alive (Revived)|
Masaru Kato is the secondary protagonist in Phase 1 and primary protagonist in Phase 2.
Frequently, Gantz addresses him as "Katō-cha", after the Japanese comedian, Katōcha. One translation of this is Kato-cha.
He is an old friend of Kei Kurono, and strives to be like the Kurono he once knew. After his grades fell and he was sent to a less-than-respectable school he took up a guardian position for those weaker than himself. While he appears to be a pacifist, he has shown himself to have violent tendencies from time to time (likely the result of repressed anger toward his Aunt). An example of this is where he beats a man to an unnecessary degree in a bathroom stall; while it should be noted that this man planned to jump and rape him, Kato had left him in extremely poor condition.
He is summoned, along with Kurono, by Gantz after they are hit by a subway train - a consequence of helping a drunken hobo off of the subway tracks. Kato and his little brother live with their aunt, but continued abuse toward his little brother and a stressed family situation cause him to obtain an apartment for the two of them.
Kato is something of a natural leader thanks to his imposing height and gentle yet powerful personality; during early missions he has a visible effect over the others, most noticeably Kurono Kei, Kei Kishimoto and Masanobu Hojo. During his third mission, the Buddha Temple mission, the final boss kills him. He, along with Kishimoto, Hojo, Sadayo, Sei and other Gantz replacements, die in this mission, leaving only Kurono alive.
Six months later, he is revived by the 'Old Man'.
At the end of chapter 237, in the preview for Phase 2, Kato states that he will revive Kurono from his death, no matter how long it takes. On his first mission since his revival, he and the rest of the team end up in Osaka instead of Tokyo and meet up with the Osaka Gantz team. Kato continues to act as leader, although the team had earlier decided on making Reika leader.
In chapter 247, Kato is abandoned by his Tokyo Teammates after Sakata Kenzo states that their main goal for this mission should be to stay alive and that Kato should forget about Kurono as well as the innocent civilians being killed. After the falling out Kato begins to doubt himself, but becomes convinced once again after he nearly lets a family be killed by not acting. He then meets Yamasaki Anzu, a female member of the Osaka team and learns more about the Osaka team and the rare 100-point alien. After rescuing Yamasaki and three other unwitting Gantz participants, Kato vows to kill the "100-pointer" and revive his best friend, Kurono.
In recent chapters Yamasaki makes Kato promise that he and his little brother will move in with her and her son. In turn, she promises to make sure he does not die. Kato is successful in killing the 100 point alien, and uses the points to revive Kei Kurono.
Personality and Fighting StylesEdit
Kato is known by the entire Gantz team as the understanding and gentle one, using force only when necessary (otherwise known as a gentle giant according to Kishimoto). Throughout the series he is constantly looking for a second way to ending the game rather than just killing the targeted aliens, though this cannot be avoided and the aliens are either killed by him or the other players. Kato has shown incredible strength even without the use of his suit. He is quite skilled with all of the equipment, with the Y-Gun being his weapon of choice most the time. Although he is usually hesitant in battle he will end up being persuaded to use lethal force upon seeing others in danger.
After defeating the 100 point alien and reviving Kurono, he shows great concern after Nishi tells them the "End of the World" in 1 week's time, he is seen at the meetings regarding that issue. In chapter 285, Kato encounters the original Kishimoto at a train station and tries to pick her up (ask her out), to her amusement we are left wondering if she accepted or not.
Surviving the Italian mission, Gantz sets Kato and the rest of the hunters free. In chapter 303, Kato is seen in his classroom clearly worried about the Katastrophe. Kato later runs into Nishi in front of Shinjuku station whilst waiting for Ayumu. Kato asks Nishi why he is smiling at a time like this, Nishi replies that everything is about to be turned upside down. Kato tells him that he is not normal, which Nishi retorts that Kato couldn't care less if everyone around them died at that exact moment. Their conversation is interrupted by the arrival of mecha falling from the sky. Kato later saves children from a robot that is attacking them, using the Y-gun to wrap it up and sent it away. Kato and the others are transferred to another location. After a brief scuttle between participants (resulting in a few deaths), they are then transported to yet another location. Kato is confused about where they are and why they are there. When one of the people out the front of the group earlier tells them the situation, then orders them to shoot the potential invaders after they get noticed, Kato yells at the other hunters not to shoot, but is forced to fight after the aliens attack him and the others. One of the aliens (the one that is targeting Kurono) appears before Kurono, Kato yells for Kurono to run. Kato appears with the others after the transfer. The leaders decided to send the hunters to different areas rather then send them to where they were first transferred from. Kato was sent to an area alone, the city could be seen in the distance.
Later on he manages to meet up with Kurono clone, Reika, Kaze and Takeshi. They all decide to head to the Gantz room in hopes of getting in contact with Gantz. They trek up the building and enter the room to find the black ball closed and not responding to them. He is present when Nishi explains about the Gantzers that transported them and has the bomb removed from his head. When Kei and Reika communicate with the other players and get a response, he wonders if someone is being transferred to the room. He watches as a male player gets transferred in. When Hyouma Takeda introduces himself, he jealously asked Kato if he was Reika's boyfriend. Kato, taken aback by this statement, denied accusation. When the last two players are transferred into the room, one of them was the nerd that promised to bring back Anzu Yamasaki. When he sees Kato, he begins to cry and tells him that he kept to this promise. Kato watched as she was transferred into the room and they had a tearful reunion.
Kato and most of the Katastrophe Team (omitting Nishi and Takeshi) are transferred up into the giant spaceship and they start rescuing people. The team manages to rescue quite a few people, but when they get back to the room, they discover that they haven't rescued that many people at all. They formulate a plan and head back up to find more of these "meat processing plants". Kato and the others head to another one and after rescuing all of the people there, they planned to move on to another one. Ryuuji requests to wait until he does something and goes and urinates in the pool where they rescued the people from. He is joined by the other male teammates, including Kato, much to the shock of the female teammates. After a while when some of the people have been transferred, a giant two headed monster and three giants crash through the wall. The team proceeds to fight off the monster and they succeed in killing the monster and the three giants.
The transfer stops and they wonder what is going on. Once the transfer had started up again, the team and the survivors get transferred to an unfamiliar area. The team formulates a plan and Kato tries to convince the survivors not to stray away from them. Anzu and the nerd offer to try and convince them.