You could try Yamato in the Encino Town Center. A step above Benihana. There's also a place in Woodland Hills, Something's Fishy. A little better than Benihahna.
Thene ther's a few Musashi's in Northridge. Not too good. benihana is better than Musashi.
Honestly, we haven't got too much good teppan here. I'd say Yamato is your best bet.