Omi is a supporting character and trusted right-hand man to Shigure, leader of the Five Katana, functioning directly under him. He frequently appears alongside Shigure during the group's operations and missions. Omi participates in key events, including a failed rescue attempt to free imprisoned members from the Imperial Army, during which he discovers their souls were extracted and sealed into objects. Following an incident where the protagonist is seriously injured by an antagonist, Omi assists in extracting both the protagonist and Shigure from danger. He is present during private moments, such as encountering Shigure and the protagonist in a bathhouse where Shigure behaves provocatively, observing their interactions and commenting on the evolving dynamic between them. His role primarily involves supporting organizational activities and Shigure's leadership, often appearing alongside other members like Yuuma during the Five Katana's operations against the Imperial Army.