Kuma’s many affiliations make many readers stumble over what kind of past he might have had.
His first filming was as a child, apparently a farmer doing manual labor. We then learn that he rose to become the king of the Sharbat kingdom, while at the same time affiliated with the Revolutionary Army as one of their leaders. After that, he became a naval warlord and eventually transformed completely into a stray robot, the PX-0.
In his most recent appearance, he appeared to be a slave of the Celestial Dragons.
In order to justify this strange sequence of events, we must start from Kuma’s childhood.
In the SBS section of Volume 63, Baby Kuma is shown with the rest of the warlords as children. Its design is quite expressive compared to the rest of the warlords. This is because he is carrying a pack of sticks on his back and reading a book called “Ninokin” which leads us to believe that Kuma was inspired by Ninomiya Sontoku. Sontoku was a Japanese philosopher, economist, agricultural leader, and most importantly a moralist. Sontoku has been immortalized by his kind actions, specifically when he fed the starving residents of Odawara, despite the Shogun’s disapproval. I think Kuma did something very similar in the Sharbat kingdom.