Even after Tekken 7's climax saw Kazuya apparently kill Heihachi, Kuma 2 never believed it, and has fought against Kazuya's forces ever since, patiently waiting for his master's return.
During the development of Tekken 7's final expansion pack ... The bear Harada enthusiastically refers to is the martial arts-trained cub Kuma who has been prominent in all mainline iterations.