KOKA, Shiga Prefecture--Like the furtive ninja groups it hosted in feudal times, this city in western Japan still has secrets to spill. In this latest instance, researchers discovered the first ...

TOKYO -- Roughly 100 "ninja" recently showed up at some tourist spots in central Tokyo during a tour of places associated with the Mie Prefecture city of Iga and the Shiga Prefecture city of Koka ...

Along with Iga, the Koka region is synonymous with ninja. The Koka Ninja are often depicted in anime and movies as the arch rivals of the Iga Ninja or as villains. But what were they really like?