To answer some "which ethnicity runs this place" I can tell you its owned by a nice Korean couple, and staffed by a mix of Koreans, Japanese and a few Caucasians.
Why does that matter anyway?
Good food is good food, no matter who cooks it. I've had awesome Italian food cooked by Ecuadorians. If you want total authenticity, go directly to Japan. Just ask your favorite sushi/teppanyaki chef where he's from. (Its probably not Japan)
//rant
Anyway, I've been here a few times and its my "special occasion" restaurant because its not very close to me.
I have yet to be served a bad meal.
I love the Sukiyaki Hot Pot! Its served in a huge cast iron crock and LOADED with noodles, veggies and meat in a wonderful rich broth.
The last few times I've gone I got the Deluxe Bento Box. It has a little bit of everything...the potato croquette is phenomenal.
Tofu Age Dashi is a favorite appetizer of mine, thick blocks of battered tofu in a rich broth.
My husband ALWAYS gets the Kimchee appetizer (hello! Korean!) And he loved that they added Bi Bim Bop (another Korean dish!) to the menu. Bi Bim Bop is a dish with rice at the bottom of the bowl, then layers of marinated beef and stir fried veggies are added and topped with an egg. Its fantasic at Kotobuki.
If Kotobuki were closer to home I'd be there every week!