Restaurants in Japan

If you want to enjoy good beef, I'd recommend "Kagayaki" in Minowa, which is close to Asakusa or Ueno. I have been wanting to visit this place but have never made it because it's always fully-booked.
It's not really a high-end restaurant and your budget is 5,400yen/person for all you can eat and drink. But the quality of beef is super. A5 ranked wagyu beef is offered here. I've never heard of any bad reputation of this restaurant.
http://tabelog.com/tokyo

I also would like to recommend some good restaurants in Yokohama. Recently I enjoyed a very very best Unagi (grilled eel fish) ever at the restaurant called "Noge Oden" for my husband's birthday. We were totally blown off! My husband loves Unagi and he knows lots of good restaurants but he couldn't remember any better Unagi than this restaurants! What we had was Shirayaki (plain grilled unagi seasoned with salt and served with wasabi) and Kabayaki (unagi grilled with Japanese BBQ sauce) of natural eel fish, which is very rare. Especially Shirayaki was really beautiful. Highly recommended if you ever come to Yokohama! Budget never exceeds 10,000yen per person.


The next door of "Noge Oden", there's also a very nice tenpura restaurant called "Toraya". (Masters of the both restaurants were classmates when they were going to school)
They also make very good tempura, sashimi and some traditional Japanese dishes.
http://tabelog.com/kanagawa/
It's not a high-end place either but I think their choice of ingredients is really great.
They have contract farmers to keep the quality of veggie at great level and master and his brother goes to market themselves to choose the best fish and shrimps for the day.
My favorite is Kuruma-ebi (big shrimp) tempura and I've never had any better kuruma-ebi than this place so far.