Masaru Katou

Katou is compassionate, idealistic and deeply protective. He dislikes killing even when Gantz identifies an alien as an enemy, and he repeatedly searches for alternatives to violence. That hesitation can endanger him, but it comes from a consistent refusal to assume that being ordered to kill makes killing morally acceptable.

His imposing appearance gives him natural authority. New participants often listen when he explains the equipment or tries to organize them, and he becomes a leader without pursuing status for its own sake.

Katou is not incapable of violence. When someone threatens another person or commits an act he considers intolerable, his restraint can disappear quickly. His morality is therefore less about absolute pacifism than about refusing unnecessary cruelty.

Katou is physically strong even without Gantz equipment. The Gantz suit magnifies that strength dramatically, allowing him to lift people with ease and fight aliens far beyond ordinary human capabilities.

He becomes proficient with the X-Gun and Y-Gun, though his reluctance to kill influences how he uses them. The Y-Gun particularly suits his preference for restraining and transferring targets rather than destroying them outright.

Katou's strongest practical ability is leadership under pressure. He organizes inexperienced participants, explains the rules when possible and continually tries to prevent missions from degenerating into every player fighting solely for themselves.

Katou and Kurono enter Gantz together after attempting to rescue a man from the subway tracks. Katou's presence immediately establishes a moral counterpoint to Kurono's initial selfishness: where Kurono hesitates, Katou acts because someone needs help.

His concern for Kei Kishimoto and the other participants shapes the early missions. During the Buddhist Temple mission, Katou continues fighting to protect the remaining team members and is killed by the Thousand-Armed Kannon.

Katou is later revived through Gantz's 100-point menu and becomes a central figure again. During the Osaka mission, he confronts the Nurarihyon alien and demonstrates how much more capable he has become while retaining his refusal to abandon other people.

Kei Kurono is Katou's childhood friend. Katou once admired Kei Kurono's courage, and their reunion eventually pushes Kurono toward becoming more like the person Katou remembers.

Ayumu Katou is Katou's younger brother and his most important responsibility outside Gantz. Katou is intensely protective of Ayumu Katou and wants to provide him with a safer home.

Kei Kishimoto develops strong feelings for Katou. Katou cares deeply about Kei Kishimoto, although their relationship never develops as simply as she hopes.

Kei Kurono and Katou increasingly operate as complementary leaders, with Kurono's combat instincts and Katou's concern for preserving life shaping the Tokyo team's direction.