Several months ago, a brothel called Gengiro appeared deep in the forest. It was said to be a paradise of food, drink, and pleasure where its proprietor, Madame Yotsuba, would fulfill all desires. However, only those she invited could even find it. One day, the son of a wealthy merchant entered the forest, announcing he had been granted that privilege, but he never returned. If rumors about Yotsuba belonging to the infamous Kakuga ninja clan were true...