[udonboi]

I want to add a sweet condiment to my kake udon. However, after speaking with a Japanese friend and doing some research online, I wasn't able come up with anything.

Currently my condiments used are as follows:
1) Thinly sliced scallion (green onion)
2) Shichimi togarashi (7 flavor powder)
3) Ichimi togarashi (chili powder)
4) Rayu (chili oil)

As far as I know, the current condiments I am using are traditional condiments used by Japanese people in Japan. I am just surprised that there is not a sweet condiment the Japanese people use to add to kake udon.

I like the taste when I add Thai sweet chili sauce, but I know this is not a Japanese condiment. Does anyone have any suggestions? I want to have something sweet to add to kake udon, but I want to keep my soup authentic.