After the Great Tokyo Earthquake, they were assigned to Tokyo in order to preserve the peace there. They were infamous under the criminals and the police for their efficiency, most of all for Senji's power. Because they defeated so many criminals, many held a grudge towards Senji.
One of them was Ikazuchi Akatsuki. He teamed up with other thugs and sent a message to Senji, challenging him. Domon decided to take the bullet for Senji and left him behind while Domon, Shindō, Kan and Momoi went to the challenge. When Senji finally arrived, they were already dead.