TV-Series
Description
Billy Katagiri is a fictional character from the anime Mobile Suit Gundam 00. Born on April 24, 2276, he stands 189 cm tall with AB blood type. A technically gifted individual, Katagiri serves as a mobile suit engineer and technical advisor, initially for the Union's MSWAD unit and later for the Earth Sphere Federation and the A-Laws.
Katagiri’s personality is fundamentally sentimental, passionate, and caring, particularly toward those close to him. He shares a deep friendship with ace pilot Graham Aker, often supporting Aker's daring requests despite finding them troublesome. However, his emotional core is most vulnerable in matters of romance. He has harbored feelings for Leesa Kujo since their university days under Professor Ralph Eifman, but he has never been able to properly date and is known to be weak when it comes to relationships with women.
This personal history drives his central motivation and role in the story. Unbeknownst to Katagiri, Leesa Kujo is the true identity of Sumeragi Lee Noriega, the tactical forecaster for the paramilitary organization Celestial Being. After discovering that Sumeragi had been using him and that she belonged to the group responsible for his mentor's death, his emotions turn negative. He becomes spiteful, vengeful, and discontent, pouring all his feelings into mobile suit development as a way to cope with his anger and hatred toward Celestial Being. This leads him to join the A-Laws, where he serves as their chief technical engineer, developing new generation mobile weapons and even perfecting the Trans-Am system for use with GN Drives based on Professor Eifman's notes.
Katagiri is a highly skilled scientist across multiple disciplines, including advanced physics, mechanical and robotic engineering, and intelligence investigation. He is one of the leading authorities on GN-Tech in the Earth Sphere, having demonstrated his prowess early on by using only visual observation to infer the nature of GN particles. His technical achievements include developing the Union Flag series, creating the GN Flag for Graham Aker in a short period despite limited data, and later developing the Masurao and Brave units.
Over the course of the narrative, Katagiri undergoes significant development. At his lowest point, he is driven by vengeance, even tearing up photographs of happier times with Sumeragi and confronting her directly with a drawn weapon during the final battle at Lagrange 2. However, during this confrontation, amid the high-concentration GN particles, he admits his regret for not properly expressing his feelings and reconciles with her. By the end of season two, he reverts to his original caring personality.
In the theatrical version, Katagiri continues his work as a technical advisor, now for the Sol Braves squadron, developing the Brave mobile suit. He reconnects with his university classmate, the flirtatious scientist Mina Carmine. Initially overwhelmed by her passionate advances, he eventually accepts her affection, and the two marry, later having a child together. Throughout the conflict with the ELS, he assists in analyzing the extraterrestrial threat, naming the aliens for the first time, and ultimately witnesses the conclusion of the battle aboard the Celestial Being mothership. His friendship with Graham Aker remains a constant, as he continues to support the pilot by developing custom machines, even as Graham pushes each test unit to its limits.
Katagiri’s personality is fundamentally sentimental, passionate, and caring, particularly toward those close to him. He shares a deep friendship with ace pilot Graham Aker, often supporting Aker's daring requests despite finding them troublesome. However, his emotional core is most vulnerable in matters of romance. He has harbored feelings for Leesa Kujo since their university days under Professor Ralph Eifman, but he has never been able to properly date and is known to be weak when it comes to relationships with women.
This personal history drives his central motivation and role in the story. Unbeknownst to Katagiri, Leesa Kujo is the true identity of Sumeragi Lee Noriega, the tactical forecaster for the paramilitary organization Celestial Being. After discovering that Sumeragi had been using him and that she belonged to the group responsible for his mentor's death, his emotions turn negative. He becomes spiteful, vengeful, and discontent, pouring all his feelings into mobile suit development as a way to cope with his anger and hatred toward Celestial Being. This leads him to join the A-Laws, where he serves as their chief technical engineer, developing new generation mobile weapons and even perfecting the Trans-Am system for use with GN Drives based on Professor Eifman's notes.
Katagiri is a highly skilled scientist across multiple disciplines, including advanced physics, mechanical and robotic engineering, and intelligence investigation. He is one of the leading authorities on GN-Tech in the Earth Sphere, having demonstrated his prowess early on by using only visual observation to infer the nature of GN particles. His technical achievements include developing the Union Flag series, creating the GN Flag for Graham Aker in a short period despite limited data, and later developing the Masurao and Brave units.
Over the course of the narrative, Katagiri undergoes significant development. At his lowest point, he is driven by vengeance, even tearing up photographs of happier times with Sumeragi and confronting her directly with a drawn weapon during the final battle at Lagrange 2. However, during this confrontation, amid the high-concentration GN particles, he admits his regret for not properly expressing his feelings and reconciles with her. By the end of season two, he reverts to his original caring personality.
In the theatrical version, Katagiri continues his work as a technical advisor, now for the Sol Braves squadron, developing the Brave mobile suit. He reconnects with his university classmate, the flirtatious scientist Mina Carmine. Initially overwhelmed by her passionate advances, he eventually accepts her affection, and the two marry, later having a child together. Throughout the conflict with the ELS, he assists in analyzing the extraterrestrial threat, naming the aliens for the first time, and ultimately witnesses the conclusion of the battle aboard the Celestial Being mothership. His friendship with Graham Aker remains a constant, as he continues to support the pilot by developing custom machines, even as Graham pushes each test unit to its limits.