Sōun Ebisugawa, younger brother to Sōichirō Shimogamo and uncle to the Shimogamo brothers, married into the Ebisugawa family to settle disputes but ultimately broke ties with his brother. Consumed by longstanding envy after losing both the position of Nise-emon and the woman he loved—Yasaburō's mother—to Sōichirō, he became head of the rival Ebisugawa tanuki family. This jealousy drove him to ally with Benten and the Friday Fellows, orchestrating Sōichirō's capture and death through a trap. As Ebisugawa leader, Sōun funds his influence and ambitions by operating a factory producing counterfeit Electric Brandy. He publicly maintains a facade of politeness and timidity within tanuki society while secretly acting ruthlessly, calculatingly, and egotistically. He encourages his twin sons, Ginkaku and Kinkaku, to bully the Shimogamo family, specifically targeting the youngest brother, Yashirō. Despite this, he demonstrates care for his daughter Kaisei, arranging her initial engagement to Yasaburō before breaking it off following Sōichirō's death. After his schemes against the Shimogamos are exposed, Sōun loses status and departs Kyoto. He later stages his own death during a confrontation with the Friday Fellows, transforming into a demon in a failed attack that results in him being shot. Surviving, he conspires with the illusionist Tenmaya, disguising himself as his estranged son Kureichirō to frame the Shimogamo family for his murder and sabotage Yaichirō's bid for Nise-emon. Kaisei uncovers his true identity upon witnessing him meet Tenmaya. In a final attempt to incriminate the Shimogamos, he plants a fake air gun in Nidaime's laboratory, but the plan fails. He and Tenmaya are subsequently dragged into hell by a demon summoned by Benten.