Works in the persecution department. From the middle-high class, he proposes to Shuurei under his father's orders despite his lack of personal interest in her. When he first appears, he is bearing many tanuki-themed accessories including a golden statue, causing Seiran to nickname him 'Tan-tan'.

He does not like putting effort into anything and thus is both intrigued and annoyed by Shuurei's continual determination to do her best. However, Tan-tan can clearly perceive a situation's complete context or a person's true character, making him a valuable asset to his department, and he tries to lessen Shuurei's naiveté by showing her the evils of the world.

Seiran considers Tan-tan to be a practical influence on Shurei and is unusually willing to engage him in conversation. Nevertheless, Seiran also likes to pelt Suou with bamboo shoots and make him pay for random purchases, calling him 'saifu #2' (wallet #2, after Ensei as #1)

Tan-tan is roped into the counterfeit paintings investigation by Shurei and ends up arresting his father, who was used in a larger plot. He saves Shurei from being fired when Riku Seiga steals her research proposal. Since then, Tan-tan has followed Shurei and re-entered the persecution department as her assistant.