[udonboi]

Nagoyankee, I thought rayu was a Japanese word?

Also, when I read the wikipedia article about rayu, it said "used in Japanese cuisine as a cooking ingredient or as a condiment."

I went to a Japanese restaurant and they actually had a botte of rayu at the table and I asked the waiter if he could make my miso soup spicy and he said just add the rayu.

I believe it is like you said though, Nagoyankee. I think it is just a chinese ingredient/condiment that has made its way in Japanese cuisine.