This blog is written by author Sachiko who is not a native speaker of English, so it may be hard to read. It is translated from the summary of Japanese page;

“Donbuku”, short winter coat

It is called “Hanten” around Tokyo, but people in Odate call it “Donbuku”.

It is like a Kimono coat filled with cotton, warm and comfortable.

In April the cold days will continue here so this is useful.