Yobu Tanaka, also known as Tank, is a member of the Japanese Blood Brotherhood.
Following the brutal treatment of the Japan after World War II when he was young, Yobu Tanaka became bitter like many other of his people and formed a brotherhood which focus on restoring their honour, even at the cost of their own lives willingly.
During his adult life, Tanaka became a notable anthropologist, and met the Canadian archaeologist Max "Wizard" Epper. During the course of their occasional collaborations, Tanaka was given the nickname Tank.
When Wizard discovered the existence of the Dark Star, which would destroy the world if they did not restore the ancient Machine, Tank saw this as the chance to destroy the world in order to redeem Japan's dishonour. With approval from the rest of the Brotherhood and Japan's government, Tank began researching the Machine with Wizard to seek opportunities to sabotage it.
Before The Six Sacred StonesEdit
Some time after the mission to restore the Golden Capstone in 2006, Tank began working with Wizard again to prepare to combat the Dark Sun. On occasion he and Wizard would visit Jack West Jr and Lily at the Great-Sandy Desert Farm in Australia. Tank gave the young girl many toys made in Japan, and she noted a sadness within him, and he noted it was due to the Japan's treatment in World War II, and despite Lily's sympathy for him it was not enough to make him change his mind about the Brotherhood or its goals.
On December 1st, the group located a chamber beneath Witch Mountain with many carvings relevant to the Machine in the entrance-way. As they noted down the various images and inscriptions, Tank and Wizard discovered that the first Pillar would need to be set 100 days before the Dark Star's return. As they had already calculated that the Dark Star was set to return in March 2008, they realised that this meant the Pillar had to be set in a little more than a week. There was little time to consider this further, as they realised there were hostile Chinese forces incoming, and so they sent all the data to Jack and deleted it from their hard-drives. Mao Gongli, the leader of the Chinese forces, confronted the pair in the chamber and decided to send Tank and Wizard to Xintan prison.
However, after being tortured at Xintan for a few days, Mao decided to have Tank and Wizard brought back due to the difficulty he was having trying to reach the Philiosopher's Stone. While being transferred on the prison train, Jack and Stretch arrived to rescue them. In the ensuing battle, Tank was freed from his captors and helped to safety by Stretch. After making their way back to Witch Mountain, Tank was left with Pooh Bear up top in order to have his wounds seen to. Once the others retrieved the Philosopher's Stone, the team headed to Mortimer Island to sort through the recently gathered information.
Tank helped to sort through the data the Killing Stone of the Maya had given them of the dates by which the Pillars had to be placed. As the First Pillar was being cleansed by the Philosopher's Stone, Tank noted that the stone had always been associated with change. While most of the team went to Abu Simbel to place the First Pillar, Tank was left with Julius and Lachlan Adamson to sort through the remaining data. However, Tank sent a message to the Blood Brotherhood, telling them to stop the Pillar-laying team.
Soon, Tank had another group from the Brotherhood come to Mortimer Island to retrieve him, and was surprised when Lachlan revealed he had understood some of what he was saying on the phone to his Brotherhood team when he gave the order for them to come in. As they prepared to depart, Tank decided that they should bring the twins with him in case their knowledge proved useful later on.
At the Japanese embassy in England, Tank and the rest of the Brotherhood looked over the data and tried to determine a way to stop Jack's team and Wolf's team from being successful in their mutual mission, occasionally asking the twins for help. When Lachlan demanded to know why Tank was doing this, he only replied that destroying the world was the only way for Japan to redeem itself.
Though the twins escaped, Tank and his Brotherhood had a plan for their mole inside Wolf's unit, Akira "Switchblade" Isaki to prevent the laying of the Second Pillar, however the plan was unsuccessful due to Jack's interference.
The Japanese Blood Brotherhood, already aware of the existence of a painted egg which showed the entrance to each Vertex that was kept in Genghis Khan's Lost Arsenal, decided to destroy it in order to prevent anyone from using it to assist locating the Vertices. Tank led some men there, and killed many of Wolf's men waiting outside before attacking Wolf's group, which had just located the egg.
After Tank destroyed the egg, Wizard arrived and unsuccessfully tried to reason with him, and then Tank then tried to blow himself up along with Wolf. However, Wolf managed to prevent Tank from detonating the bomb properly, and was heavily injured. During the escape from Mao's incoming forces, Jack decided to take Tank with him, believing he had information they might need.
Some time later on-board the Halicarnassus, Tank awoke to realise his failure, as the images from the egg had been copied onto a shield. Undeterred and still unwilling to help, he then revealed the the Third Vertex's location beneath Hokkaido was already known to his government, and protected by a Naval fleet to prevent anyone from getting in. However Jack and Wolf's teams were successful in laying the Pillar, getting past all of the Japanese defences.
When Carnivore's men found the Halicarnassus and kidnapped Sky Monster and the injured Tank, taking them to Carnivore's lair. While Tank was shackled to the wall, Carnivore noted Japan's desire to see the world destroyed, and because of this he would have no use for him, shooting Tank in the head without warning.