Shigematsu was the Vice-President of the IGO, whos power in the IGO is only superceded by Ichiryuu himself. It's later revealed that Shigematsu was a spy who infiltrated the IGO under the employ of the rival organization NEO.
Not much is known about Shigematsu's origins. He was however seemingly a close friend of Mansam's before defecting to the NEO organization. It was revealed that Ichiryuu hand picked Shigematsu for the position of Vice President, partly because of Shigematsu's level of ambition.
Shigematsu is a secondary antagonist created by Shimabukuro Mitsutoshi for the series Toriko.
Shigematsu was originally the Vice President and Second in Command of the IGO. However he switched his allegiance to NEO. It can be assumed that he was defeated and brainwashed by Joa in order to cause him to defect.
Shigematsu is a tall and muscular middle aged man with, slightly tan skin, a full beard and mustache and dark brown hair, with a streak of gray down the middle.
Shigematsu appears to be a stern man. When there was talk of Heavenly King Zebra being released from Honey Prison, Mansam supported the idea as did President Ichiryuu. However Shigematsu did not and felt Zebra should remain incarcerated. Eventually Ichiryuu overruled this and ordered Zebra's release.
Mansam - The two had shared a seemingly decent relationship and they were closest in rank within the IGO, Shigematsu being the second in command and Mansam being third in command. However after defecting to the NEO organization, Shigematsu back-stabbed Mansam, figuratively and literally.
Shigematsu meets with Mansam and requests his assistance. He expected that the Bishokukai would come to take back their destroyed GT Robo and wanted Mansam with him in case the opponent was too strong. Indeed, Bishokukai Vice Head Chef Grinpatch arrived, however he was not someone capable of defeating the powerful duo. Shigematsu and Mansam powered up and that alone was enough to make Grinpatch realize that he was outmatched and he retreated.
Shigematsu abruptly arrives where Mansam is battling against the numerous Giant GT Robos. Before Mansam even takes notice of him, Shigematsu's beast impales Mansam through the back. A stunned Mansam falls to the ground. However he remembers that he promised never to lose a fight unless it were against President Ichiryuu, and he gets back up. The fight is not seen but both men survive the ordeal, Shigematsu seemingly unscathed. Shigematsu is next seen with all of the NEO members back at their headquarters and with Joei leading, they head off to celebrate their victory over both the IGO and the Bishokukai.
Shigematsu suddenly appeared on the plans of Food King AIR as Toriko and his allies were celebrating. Shigematsu had stopped the hearts of nearly everyone present, which would have resulted in their deaths had Brunch not restarted them with his lightning. But this turned out to be a distraction for the sole purpose of assassinating Chef Komatsu at the hand of Teppei, Shigematsu's ally, who pierced the helpless chef through the chest and crushed his heart.
At this, Sunny and Zebra proceeded to brutally kill Shigematsu's beast partner, all the while Toriko's rage growing. After warning Shigematsu and his partners, Shigematsu's ally Kariu stated he intended to take out every person in Toriko's company, but before he could even get off an attack, Toriko killed him. Next was Boneless, then finally it was Shigematsu's turn. Toriko rushed Shigematsu who was helpless to counter Toriko's speed, then was launched in the sky by Toriko's Mugen Kugi technique. Toriko claimed this was a merciful death. Shigematsu was sent soaring through the sky, shooting through beasts trying to eat him until he was finally ripped to shreds by 4 giant bird beasts. The moment before his death, Shigematsu regained his old senses from before he was altered by Joei. In his final moment, he apologized to Ichiryuu.
None of Shigematsu's powers and abilities have been revealed yet, but it can be assumed that he has Gourmet Cells and given that he was the Vice President of the IGO directly under Ichiryuu (said to be the strongest man in the world) Shigematsu is likely one of the strongest people alive.