Almost a millennium ago Yamamoto Genryūsai Shigekuni was to be placed at the head of Squad one, to become the Captain Commander of the thirteen court guard squads. The appointment was to the surprise of no one and it was predicted by many that he would become one of the most powerful men to ever sit atop the Seireitei. Become. It was only said because he was not yet the most powerful, because there was another. Gorou Nobunaga. The man was infamous, his power had become legend as would the captain commanders. Nobunaga however powerful he might have been, was not approached for the position of Captain commander for he was deemed an 'unstable entity'. The members of central 46 did not trust him from the beginning but the reason they did not act was due to his volatile nature, and a man with that much power and such short a fuse would not take kindly to the sanctions central 46 would have placed upon him.
Their worries were about to be put to rest however. The ceremony was complete and the newly christened captain commander Yamamoto was to give his first edict as the head of the Gotei squads. To strip the rank and status of the Shinigami Gorou Nobunaga, to imprison him. Stares of surprise and concern were seen on almost every face in the crowd, but once face was still, calm. Nobunaga himself took his sword from his side, he stepped towards the Captain commander as the surrounding Captains prepared to draw in anticipation of the fight that would ensue Yamamoto's order. Nobunaga did not draw however, he fell to one knee and raised his sheathed sword to Yamamoto, "So be it" he said before he was escorted from Sokyoko hill.
The news spread in moments and whilst the majority were in favor of the mans imprisonment a particular minority was not. Nobunaga's squad. After fighting tooth and nail with the central 46 they were brought to their knees in reluctance, they could not do a thing, they could not save their beloved Captain. Soon after several members of Nobunaga's squad disappeared from the Seireitei, and after searches were unsuccessful it was clear they were not even in soul society.
Jakakumei (邪革命 – wordplay meaning ‘revolution of vengeful ghosts’) are a group of rogue Shinigami who are called “The Jacks” by locals. They are known for their stealthy demeanor and wearing masks. Although their members are not regulated strictly in regards to uniform, they are all required to wear a blue robe and carry a personal mask.
The Jakakumei were formed after the imprisonment of Gorou Nobunaga, a former captain of the Gotei 13, by captain Yamamoto himself. His squad put up resistance to the act, but eventually had to flee from Seireitei. These Shinigami and their descendants are the members of Jakakumei, and now call the Rukon-district their home.
"Ahhh this sucks, why are we always the ones who have to check out any and all weird readings in the human world?! Nothing ever actually turns up..." The Shinigami turned to view his compatriot arms crossed,
"Oh be quiet you fool! your distracting me! Captain Kurosutchi wants this abnormality documented and checked" He turned back to his work mumbling under his breath the curses of squad eleven attention spans. "Hmm. That's peculiar." The Shinigami took to his feet as he inspected the readings he was given. Pointing his device to the sky and turning in a circle as if trying to get signal his brow lowered as he began to pinpoint the readings location. "It's...It's right about..." his expression turned from confusion to curiosity as he looked to a rooftop not far from the pair atop which a silhouetted man stood, his robes waving in the thin breeze.
"Hey, Kouta." pointing towards the figure he gained the attention of the squad eleven member. "It's him, these readings are coming off him."
"Finally! something interesting, stand back Iro." The Shinigami whipped his Zanpakuto from it's sheath holding it out to his side. "Come and get..." he roared in the typical fashion of squad eleven, but before he finished his taunt the man atop the building blurred and dissipated, and in a split second a blade crossed his neck and split his skin apart.
The scientist tasked with gathering information on the strange readings was faced with the terrifying answer. Time slowed as fear crept into his psyche, a man stood before him, a white mask not dissimilar to a Hollow covered his face, Blue robes still fluttering in the wind as the decapitated head of his guard fell from his neck.
"What squad are you." Asked the masked man as he rested his sword on his shoulder. The underling of Captain Kurosutchi could hardly draw breath let alone answer the killers question. "I suppose it doesn't really matter, run back to your captain Shinigami! And tell him the Jakakumei are knocking at the door of Seireitei." and with his order several other people flashed into view behind him, all wearing the distinct blue robes and masks.
Iro turn tailed and ran as quickly as he could from the unknown assailants, he would tell his captain who would in turn tell the Captain commander and although he was too frightened to realize it just yet, Iro was about to deliver the message to start a war.
"And so begins the Captains emergency meeting!" Head Captain Yamamoto stamped his staff and his authority over the nine other figures in the room. "Captain Kurosutchi. Please tell the other Captains of the events that took place yesterday." The slight, bony and strange character that was Mayuri stepped out from the rank of Captains to address the room. "Yesterday I sent one of my squad members in an attempt to collect data on some strange fluctuations I have noticed in the human world. He was issued with a barbarian of squad eleven as protection" his eyes darted to the man-mountain Kenpachi Zaraki whose expression did not change. "During this task the two men happened upon an assailant. He decapitated the squad eleven braggart and sent my subject back to soul society with intention the news would reach us."
"Pff, let me go find him, guy sounds like he has balls" exclaimed Kenpachi.
"They call themselves the Jakakumei, and they are not to be taken lightly judging by the readings we received." continued Mayuri. Captain Hitsugaya was next to step forward to question the research and development captain. "How many were they?" The young Captain asked.
"We do not know, but my Shinigami believes he saw four maybe five more once his guard was killed.
The Captain commander stamped his staff on the wooden floor once more. "Captain Byakuya and captain Hitsugaya, you will send your lieutenants to the human world in an attempt to make contact with this group and to find their intentions. We will not stand by as Shinigami of the Gotei thirteen are slain!"