Ninja Wars is a Kara-Tur adventure published in 1990 by TSR.
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Behold The Shining Temple of Bishamon!
Located above the city of Aru on the island nation of Wa, this shrine is the focus of a great pilgrimage. Every year, thousands of people travel here to celebrate the Ceremony of the Three Thousand Steps. For townsfolk and travelers alike, it is a time of great celebrations and revelry.
For Benju Matsutomo, Daimyo of Aru, it is a time of worry and concern. Something is wrong this year. A political rival has hired a clan of ninja to disrupt the pilgrimage and disgrace Matsutomo. But the daimyo has his own ninja, and just to be safe, he decides to hire a party of adventurers to make sure everything runs smoothly.
Of course, it doesn't...”