TV-Series
Description
Masaru Katou is a seventeen-year-old high school student and one of the two main protagonists of the series. He and his childhood friend Kei Kurono die in a train accident while attempting to help an unconscious man who had fallen onto the tracks, and are subsequently transported to the mysterious Gantz room. Katou stands 192 centimeters tall and has shoulder-length black hair.

Katou was orphaned at a young age and lives with his younger brother Ayumu, whom he fiercely protects. After staying with an aunt who treated them poorly, he saves enough money to rent an apartment for himself and his brother. This responsibility drives much of his motivation and reinforces his protective instincts.

Katou is defined by his strong altruism, compassion, and sense of justice. He is naturally inclined to help others, often taking on a leadership role within the Gantz team because of his moral authority and willingness to stand up for weaker individuals. However, his reluctance to inflict harm on others severely limits his effectiveness in the violent missions of the Gantz game. He often seeks non-lethal solutions and opposes unnecessary cruelty, which puts him at odds with the brutal nature of the game.

In the Gantz missions, Katou possesses the standard abilities granted to all players: a black suit that enhances his physical strength, a Gantz gun, and brief invincibility during mission start. His combat skills are average, and his inability to strike opponents makes him less formidable than many other participants. Over time, he becomes more strategic in his thinking, looking for ways to protect others without sacrificing his values.

Katou's role in the story evolves significantly. He initially serves as a moral anchor for the team and a counterbalance to the more selfish Kurono. He dies during the Rateiin temple mission but is later resurrected near the end of Phase 1 by fellow Gantz member Yoshikazu Suzuki. After his return, Katou manages to kill the alien known as Nurarihyon, earning one hundred points, which he uses to revive Kurono. His resurrection marks a turning point in his development, allowing him to reflect on his past experiences and grow as a leader in subsequent missions.

His key relationship is with Kei Kurono, his childhood friend. Their bond is deep but fraught with contrasting worldviews: Kurono initially acts out of self-interest, while Katou prioritizes the well-being of others. Katou's death and later resurrection profoundly affect Kurono's own character growth. He also develops camaraderie with other team members, such as Kei Kishimoto and Yoshikazu Suzuki.

Throughout the series, Katou's character embodies themes of sacrifice, morality, and the weight of responsibility. His journey shows him learning to navigate the moral complexities of the Gantz world while remaining true to his core desire to protect others. His most iconic moments often involve him taking charge in chaotic situations, such as during the Oni Alien mission, where he demonstrates both resolve and compassion.
Cast