was a term given to four samurai during the Bakumatsu era in Japanese history. The four men were Kawakami Gensai, Kirino Toshiaki (also known as Nakamura Hanjirō), Tanaka Shinbei, and Okada Izō. They opposed the Tokugawa shogunate (and later, supported the Meiji Emperor). These four samurai were warrior elite and widely considered undefeatable by normal people. The word hitokiri literally means "manslayer" or "man cutter," as the kanji 人 means person, while 斬 can alternatively mean slay or cut.