This restaurant of long standing is one of the best in Shinjuku for teppanyaki and steak. They have several steak sets options of less than ¥2,000 for lunch. If you want something really special, for dinner, they serve some Japanese black cattle wagyu teppanyaki courses for two that are between ¥12,500 and ¥25,000. There are many counter seats from which you can see the chefs cook the meat for you on the iron plate so you get a true Japanese teppanyaki experience.
Teppanyaki Steak Kitanzan (鉄板焼き ステーキ 湛山)
Kitanzan is a chic restaurant where you can experience a cuisine that is a fusion of French and Japanese styles. Although a bit pricey at ¥10,000 or more, the evening courses are quite the feast for the eyes and mouth. The steak is just perfectly cooked to your liking. Aside from the steak, you can have some teppanyaki seafood as well. This restaurant is located in the heart of Kabukicho.
Misono (ステーキ みその 新宿店)
There are two reasons to go to Misono. One is for the succulent marbled teppanyaki steak made right before your eyes. The other reason is for the stunning night view of Shinjuku you get from the restaurant located on the 51st floor of the Shinjuku Sumitomo Building. The prices are reasonable for lunch (about ¥3,000) but evening courses can be quite expensive (about ¥15,000). Here, you can try Kobe beef among other types of fine wagyu.
Teppanyaki Yamanami (鉄板焼 やまなみ)
Yamanami is a high-end restaurant where you can enjoy Kobe and Hida wagyu beef with courses of over ¥10,000. Aside from steak, you can also have some teppanyaki lobster. There is a view on a beautiful Japanese garden from some seats and you can also make a reservation to have a private room. The entire establishment is non-smoking.
Le Monde (ル・モンド)
This is just bonus information because to be fair, this isn't a teppanyaki restaurant per say, as the meat is cooked on a grill, but still, if you love meat it's a must go! This is by far the most popular steakhouse in Shinjuku. When you want to have some super savoury steak at a really reasonable price this is the place you should go. Le Monde is so popular that you might have to wait in line for up to an hour because there are only 10 counter seats. The rib roast 150g steak set meal is just ¥1,000. The meat is super juicy and tender. This place has many female fans even though it has the atmosphere of a very casual diner.