From Wikipedia:
山田太郎 (Yamada Taro, a common male name), 山田花子 (Yamada Hanako, a common female name), 名無しの権兵衛 (Nanashi-no-Gombee, 名無しの meaning nameless, 兵衛 (hyoue) meaning member of the imperial guard and 権 (gon) being used to describe titles or positions, "Nameless member of the imperial guard". The term was transformed into nanashi-gonbee, meaning colloquial "Nameless Mr. So-and-so), 何野某 (Nanno Nanigashi), 土左衛門 (Dozaemon, a drowned corpse)