From publisher blurb:
After his defeat at the hand of Oda Nobunaga, the great Daimyo Azai Nagamasa commits seppuku. The only hope for what is left of his retinue is a secret alliance with the Takeda clan, the only one strong enough to oppose Nobunaga. However, Takeda Shingen demands a hostage to guarantee the loyalty of Nagamasa’s former retainers. The hostage must reach the Shinano province without Nobunaga being aware of his presence, but the road passes through Oda territory. A group of brave adventurers must accompany the hostage in his dangerous journey.
So begins the Rise of the Yōkai Koku campaign, a Revolution D100 roleplaying adventure set in the Sengoku period of the Japanese middle ages. Many adventures await our noble heroes on their path to restoring their clan fortunes, and not all threats will be human in nature.