You and maybe six other people on Earth know who that is.
If you had said six other people on this forum, then that may be true. But he is legendary in his native Japan. Even in the West, the triumvirate of Japanese masters in terms of cinema is widely considered to be Kurosawa, Ozu, and Mizoguchi.
Last night I watched the first half of a 1975 documentary,
Kenji Mizoguchi: The Life of a Film Director. The documentarian seems to have tracked down and interviewed anyone who ever had contact with the great man, from his longtime artistic collaborators down to people who knew him as a passing acquaintance. He was known to be a meticulous fusspot and perfectionist. His two great passions in life were said to be women and sake. In one instance, he was stabbed in the back (literally) by a prostitute who had fallen in love with him and whom he had jilted. A few years later he was in a sauna, and a young man remarked on the scar. Mizoguchi said to him, "until you have a scar like this one, you will never understand women."