Grossular occupies the role of section chief as one of ACCA's five chief officers, governing the kingdom's thirteen autonomous states. He maintains a reserved and enigmatic demeanor, distinguished by long white hair and grey eyes.

Convinced that Jean Otus, second-in-command of ACCA's inspection department, is implicated in a rumored coup d'état, Grossular cancels the department's planned termination. He places Jean under surveillance to investigate potential sedition, persisting in his suspicions even as fellow chiefs express doubt about the coup's existence.

A significant event from his past involves assuming responsibility for a train accident that claimed the life of Princess Schnee, a royal family member. This incident forms a key aspect of his background within the organization.

Operating within ACCA's leadership during escalating political tensions, Grossular interacts with fellow chiefs Lilium, Pastis, Pine, and Spade. He monitors ACCA's district activities for signs of instability or treason, his actions contributing to the underlying tension surrounding the kingdom's future, particularly during Prince Schwan's transition of power.