I found the Japanese equivalent of jellyfish salad that is usually served in dim sum restaurant! The name's chuka kurage.

Apparently Japanese people are known to make chuka out of other ingredients too. Chuka made from baby octopuses and seaweed are equally popular, they are called chuka idako and chuka wakame, respectively.

Chuka kanimayo, as you might have guessed, is crab + mayonaisse. I don't remember the name for chuka made from salmon skin, though.

The sauce they are mixed with are made from sesame oil, vinegar, sugar, chili oil, chili sauce, mirin and sesame seeds. One variation adds mayonnaise to the mixture. Another chopped chili. Another soy sauce. Another chopped shallot. :E Yes. I dislike the one with the shallot.