Kanna is a friendly rice village with a problem. Every year during harvest, huge mechanical robots, known as the Nobuseri, come and steal away almost all of the rice that had been harvested that year. Not only that, the Nobuseri are becoming more demanding, now taking women and children in addition to rice.

The elder of Kanna has declared that to protect the village they must hire samurai. However, they have no money and thus must find samurai willing to protect the village for the price of all the rice that he/she can eat. He sends three members of the village out to the city to begin looking. And thus the journey begins...(Wikipedia)