Keisuke Yamao

Yamao initially appears subdued after his years away from Kitanosawa. His return forces him to confront childhood friends whose lives were profoundly affected by the traffic accident for which he was imprisoned.

He is capable of concealing his intentions behind an outwardly restrained demeanor. The apparent remorse surrounding the hit-and-run hides both his involvement in a far more serious earlier crime and his willingness to endanger an entire community to recover what he lost.

Yamao is driven by greed and self-preservation once his true motives emerge. He plans patiently, removes people who threaten to expose him and accepts potentially catastrophic consequences for Kitanosawa if they allow him to recover the stolen jewels hidden beneath the reservoir.

Yamao is an ordinary human without supernatural abilities. He nevertheless demonstrates practical knowledge of explosives and sufficient planning ability to coordinate several acts of sabotage.

He is physically capable and willing to use violence when cornered. His crimes involve an electroshock weapon, explosives and a firearm, while his larger plan requires detailed understanding of the Kitanosawa dam and the movements of its personnel.

Yamao also shows considerable capacity for concealment. He hides stolen jewels near old Kitanosawa, allows investigators to focus on the hit-and-run for which he is arrested and keeps the jewelry robbery concealed for eight years.

Yamao returns to Kitanosawa after eight years in prison, rejoining childhood acquaintances Mizuki Tono, Fuyumi Tachihara, Takehiko Muto and Shogo Hikawa. His sentence resulted from the traffic incident involving Mizuki's younger sister Natsuki Tono.

The appearance of Hikawa's body and the recovery of Touma Tachihara from an eight-year coma lead Conan Edogawa to examine what happened around the village before the dam was constructed.

Conan discovers that Yamao had robbed a jewelry store and killed its owner shortly before the traffic accident. He was carrying the stolen jewels back toward Kitanosawa when his car struck Natsuki. Touma subsequently saw evidence of the robbery, and Yamao pursued the child before Touma fell from a cliff.

Yamao hid the stolen jewels in old Kitanosawa, expecting to retrieve them after serving his sentence, only for the village to be submerged by the new dam. He therefore engineers the attacks in Tokyo, destroys communications near the village and plans to blow up the dam so that the water will drain and expose his hidden loot.

Hikawa discovers the connection between Yamao and the old robbery, prompting Yamao to murder him. Yamao later detonates the dam, threatening the relocated village before Conan creates an avalanche to divert the resulting flood.

Mizuki Tono is one of Yamao's childhood friends. Her younger sister was struck by Yamao's car eight years earlier. [Touma's recovered memories reveal that Mizuki Tono had accidentally pushed her sister into the roadway moments before the collision.](#spoiler)

Natsuki Tono was struck by Yamao's vehicle as he returned toward Kitanosawa. The incident led to his imprisonment and became the publicly known explanation for his eight-year absence.

Touma Tachihara witnessed events on the night of the accident. [Keisuke Yamao pursued the seven-year-old after realizing he had seen evidence of the stolen jewels, leading to the fall that left Touma unconscious for eight years.](#spoiler)

Shogo Hikawa is another of Yamao's childhood friends and later works as an insurance investigator. [Shogo Hikawa uncovers Yamao's connection to the jewelry robbery, and Yamao kills him to prevent the information from interfering with his plan.](#spoiler)

Fuyumi Tachihara and Takehiko Muto are fellow childhood friends from Kitanosawa who reunite with Yamao after his release.

Conan Edogawa investigates the connections between Yamao's past and the new attacks. [Conan Edogawa ultimately reconstructs the robbery, the reason for the dam sabotage and Yamao's involvement in Hikawa's murder.](#spoiler)

Yuuichiro Asakura is the Tokyo governor whose planned visit to Kitanosawa becomes relevant to Yamao's scheme. Yamao's attack on the Touto subway is intended to disrupt the governor's schedule and help clear personnel away from the dam before its destruction.