Hyakko Party (百虎党, Hyakko tō) is an Anti-governmental organization led by Naotora Momose, who claims to be the last of Fuhei-Shizoku (former samurais). In the name of "Heaven’s justice", they kill governmental officials and war profiteer in order to save the poor and revive feudalism.
The Hyakko Party was being funded by Alma Trading Company. They have been attacking doctors and other specialists researching certain artificial body parts and blood, and taking their research and giving it to Kershner. When the vampires got what they needed, they wanted to stop funding the Hyakko Party, but that only angered Naotora, who launched an attack on Alma Trading Company. They killed the workers at the company and got information on Kershner and the new weapon project testing they were doing.
The Hyakko Party then went after Kershner and the train and hijacked it. Upon finding the new weapon, Klarwein was operating it, making it look like it was mimicking Naotora movements. When Naotora led his guard down, Klarwein using their new weapon killed Naotora. When the rest of the party learned about their leaders death, they decided to ran and save themselves.