Katrina Tobey hails from an American espionage dynasty, entering the field herself during her youth. A mission led her to encounter Shin, whose compelling personality drew her into the Tsukikage organization dedicated to battling criminal syndicates. Within Tsukikage, she took Hatsume Aoba as her disciple, training her in espionage and forging a mentor-protégé bond; Hatsume would later rise to prominence within the group. Advancing age gradually lessened the effectiveness of the Spyce substance enhancing Tsukikage operatives' physical abilities, leading Katrina to step back from active field duty, a transition shared by other senior members consistent with the substance's limitations.
Post-retirement, she assumed management of Wasabi, a curry restaurant and café serving as a public front for Tsukikage's covert operations. The establishment conceals the entrance to the group's underground base, placing Katrina in a critical support role. She remained involved in strategic decisions, notably collaborating with Mei Yachiyo on a high-stakes triple agent infiltration of the rival syndicate Moryo. Katrina was one of only two individuals privy to Mei's true loyalties throughout the perilous mission.
Her connection to current Tsukikage members extends beyond logistics; she once shared personal past anecdotes with Momo Minamoto, visibly moved during the recollection. She continues to oversee Wasabi's operations, ensuring its dual function as a legitimate eatery and vital intelligence asset against criminal threats.