From the introduction:
A One-Round Legend of the Five Rings Adventure
This scenario takes place in the Winter Court of Akodo Toturi, the Daimyo of the Akodo family and Champion of the Lion Clan. The PCs are among a small group of guests (20 in all) invited to attend the Winter Court, where they will witness the marriage of Akodo Nishi, Toturi’s favored cousin, to Kaiu Yutaka, a Kaiu Battle Master of the Crab Clan, to seal a treaty between the two families. Unfortunately, one of the other guests, Akodo Kafu, has become the target of a vile Shadowlands creature, the Oni no Ianwa. This creature forces Kafu to commit a series of ever-more-destructive acts, disrupting the peace and harmony of the Winter Court. If the PC’s are inquisitive, brave, and a little lucky, they will be able to find out what is happening and drive off the Oni before it is too late.