You didn't quite specify the "cuisine" you were interested in, is it just Japanese???? If you want a "quick" fix of Una-Don you might find it in the Deli at Nijiya on Convoy.
For other interesting things...the Shanghainese have a "famous" (to quote my wife)Eel dish. I've tried it at New Shanghai Restaurant at 4681 Convoy Street, there was nothing especially memorable about the dish, tho' I ate a really great salt-pepper deep fried pork chop there.
I also know that when we lived in Rowland Heights the Korean establishments there made a wonderful broiled Eel...but have not looked for that here in SD.
You should be able to find eel at almost any decent Japanese restaurant or sushi bar. The Japanese name for it is unagi. If all you want is an eel dish, I like unagi donburi--which is mostly just eel and sauce on top of steamed rice. I'll bet if you call 5 Japenese restaurants, at least 4 will have eel.