In Japan as in China, there is a tradition of officials being chosen from members of politically prominent families for senior positions and, often, those politicians exhibit similar political leanings as their forebears.
At the very top, Japan's prime minister, Shinzo Abe, is the scion of a political family. His father, Shintaro Abe, served as foreign minister and his mother was the daughter of Prime Minister Nobusuke Kishi who, though classified as a Class A war criminal, went on to become prime minister in the 1950s. Abe has said that he carries Kishi's DNA.
Similarly, in China, the "core leader," President Xi Jinping, is the son of Xi Zhongxun, regarded as among the first generation of leaders of the People's Republic of China. China's ranks of senior officials are filled with "princelings," including those who gained their status through marriage.