It ends in the sea.

Nagasu faces the Ariake, a sea of tides and mudflats. In the grounds of Shioji Shrine, men in loincloths fight over a round target woven from straw and hemp - sixty centimetres across, six kilos in weight. Bakai, in the local speech, means to seize, to wrestle away.

The scrum spills out of the shrine, moves into the streets, and finally goes down to the shore. The Ariake in January is bitterly cold. The men wade in anyway, and the thing ends with their arms raised in the water.

Afterwards the target is cut into small pieces and carried to the houses of the parish. Set on the household shrine, each fragment becomes a year's protection. What was fought over is divided finely and returned to everyone.

It looks like a spectator's festival, but you can join it. A phone call to the town office is enough. There is something strange about being let straight into a thing that has been going on for eight hundred years.