Japanese people set up New Year's decorations at the gate or on the door. Those were originally for welcoming local gods. A common decoration costs 1800 yen ($17.31 €12.68). I bought a cheap one as usual at Seiyu. It cost 498 yen ($4.79 €3.51).
decoration on the door
We have to put it before December 30th. It is said setting it on December 29th or 31st attracts ill fortune. Dec 30th is OK.
We remove the decorations around January 7th.
This is a common type decoration in Tokyo.