Kato functions as primary butler to Marucho Marukura, delivering consistent logistical support to the Battle Brawlers throughout all seasons. He appears approximately 70 years old, distinguished by gray hair, a large mustache, and round glasses, consistently attired in a formal black suit with a white shirt and burgundy bowtie. His primary duty involves piloting a personal airship for Battle Brawler transport. This vessel features an orange-and-white design in earlier seasons, equipped with sleeping quarters and a rear deployment hangar. During *Mechtanium Surge*'s second arc, the airship returns with a smaller blue design and integrated Bakugan-scanning technology. Kato pilots this craft to facilitate the team's mobility on critical missions across every season. Within the original *Bakugan Battle Brawlers*, Hal-G attempts to infiltrate the team by impersonating Kato. This deception unravels when Shun Kazami spots inconsistencies, particularly the imposter's failure to use Kato's habitual polite address, "Master Marucho". Kato maintains a supportive presence in *New Vestroia*, assisting the team during conflicts there without direct battle involvement. His role remains minor in *Gundalian Invaders*, confined to a brief appearance at Marucho's residence alongside Ren Krawler. *Mechtanium Surge* reveals expanded capabilities for Kato. During the first arc, he collaborates with Kyosuke Marukura (Marucho's father) on technological projects, demonstrating proficiency in engineering and systems development. By the second arc, he relocates to Bakugan City, continuing operational support, though specific activities remain unelaborated. Later seasons indicate reduced direct service to Marucho, as Kato transitions to working under Kyosuke Marukura's employ. Kato stands as one of only five recurring human characters—alongside Dan Kuso, Shun Kazami, Marucho Marukura, Miyoko, and Julie Makimoto—to appear in every season, including both arcs of *Mechtanium Surge*. His interactions reflect a polite demeanor and unwavering loyalty, consistently addressing Marucho with formal respect. Personal relationships, family, or activities outside his duties to the Marukura family and Battle Brawlers remain undefined.