And welcome to the Awa Mountain Dog blog and shop.
The tradition stems from a legend that the Japanese sun god, Amaterasu Oomikami, shut himself away in a cave. Of course this was a major problem since without the presence of the sun god the earth was plunged into perpetual darkness. The other gods devised a plan to get him out of the cave by throwing a party in front of his door. The trick worked, Amaterasu came out, and they quickly pulled the god into the open and put a 'shimenawa' on the door so it was impossible to go back in.
And there you have your daily dose of Japanese culture. Happy belated New Year everyone.