Well, the short answer is, the Japanese immigrants came over, and a bunch of the bakers introduced them -- including at least one in Los Angeles, and one here in San Francisco, called Benkyodo, which is on the corner of Sutter and Buchanan.
简单说来，日本移民来到了美国， 一群面包师就引进了他们。 洛杉矶至少有一家， 在旧金山这里有一家。 名字叫做学习堂。