Sumito Hisagaki

Hisagaki is primarily characterized through his professional and clandestine dealings rather than his everyday personality. As the Onoe conglomerate's lawyer, he occupies a position of trust that gives him access to information concerning the family and its assets.

His willingness to negotiate with Brian D. Kadokura over the Onoe treasure shows that his loyalty to the family is compromised when personal opportunity becomes involved. His actions place the treasure in danger of falling into the hands of an international arms dealer.

Hisagaki is a professional lawyer familiar with the Onoe family's business and legal affairs. His position gives him access to information unavailable to outsiders and makes him knowledgeable about matters surrounding the family's property.

He has no established exceptional combat abilities. His inability to defend himself effectively against an expert iaido practitioner becomes significant when the investigation reconstructs the attack against him.

Hisagaki's involvement becomes central to the murder investigation running alongside Kaitou Kid's attempted theft of swords from Takuzou Onoe. The police discover Hisagaki in Hakodate's warehouse district with distinctive crossed sword wounds.

The case becomes connected to Brian D. Kadokura, a Japanese-American arms dealer searching for the Onoe family's hidden treasure. Conan Edogawa and Heiji Hattori gradually determine that Hisagaki's activities and the sword attacks are connected to the same historical mystery.

Hisagaki had begun dealing with Kadokura concerning the treasure. Ryoe Fukushiro, acting on Tadayuki Onoe's request to ensure that the treasure could never be misused, regarded Hisagaki's cooperation with Kadokura as a threat and killed him.

Ryoe deliberately uses techniques that direct suspicion toward his son Hijiri, while Conan eventually identifies Ryoe through his iaido stance and an injury characteristic of his sword technique.

Takuzou Onoe is the head of the conglomerate for which Hisagaki works as legal adviser.

Brian D. Kadokura seeks the Onoe family's hidden treasure. [Sumito Hisagaki secretly deals with Brian D. Kadokura, creating the immediate threat that leads to Hisagaki's murder.](#spoiler)

Ryoe Fukushiro has longstanding ties to the Onoe family. [Ryoe Fukushiro kills Hisagaki to prevent the treasure from falling into Kadokura's hands.](#spoiler)

Hijiri Fukushiro becomes connected to the investigation because of the swordsmanship used in Hisagaki's murder. [The evidence is deliberately arranged to make Hijiri Fukushiro appear more suspicious while concealing his father's involvement.](#spoiler)