The central character of the rest of the series after the first few volumes, Takagi started out in the early volumes as a mentor character to the protagonist Matsushita. But his never-say-die attitude, penchant for exaggerated macho posturing, and over the top Osakan sensibilities won over readers, and he quickly became the most popular character in the series. And as his popularity grew, the series became more and more centered on him, until he replaced Matsushita as the series main hero (or rather in his case anti-hero). He is the successor to Morigami Shingo as the Karate Club's captain. Morigami also passed onto him the mantle of "The Soul of Osaka III", a title which essentially means he oversees all the youth gangs in Osaka, and that all the other gang leaders answer directly to him. This title is obviously widely coveted by the other gangs, and Takagi is challenged for it frequently throughout the series. As a gang lord Takagi certainly can't be called a "hero", but he does have his own set of principles and a personal code of honor, making him fall more in line with a traditional anti-hero. Takagi grew up an orphan and doesn't really know who his real family was, but he strongly suspects Jinrai Isao (the original Soul of Osaka) to be his brother. As the series continues, Takagi finds himself forced to defend his title again and again from other ambitious would-be gang lords which takes a toll on him. So much so that at one point he finds himself re-evaluating his life and decides to leave the gang wars of Osaka behind him and start a new life in Tokyo. But even there he cannot escape getting involved in the raging battles between the Tokyo youth gangs, and it isn't long before he is forced to return to Osaka. But through it all he never loses his trademark goofy sense of humor. He is prone to making ridiculous and often corny Engrish puns, which only he himself finds hilarious. He also has a soft spot for Matsushita, and will come to his defense when he's getting picked on or losing a fight.