Had dinner at a restaurant named Submarine. It's close to Shinjuku station. Went there rather early on a Friday night. I think we arrived around 18:00, 6 pm.
Turns out that you should call them to book a table. Don't how we should manage to do that since we don't speak Japanese, and they don't speak English. We could however sit by the bar and eat.
The restaurant doesn't have an English menu, so ordering means Russian roulette. You don't know what you get. A safe bet is to point at things that other people have ordered.
Ordering drinks/cocktails is also Russian roulette, but the sections in the drink menu has English headings for each section, so you do at least know that you were ordering something that contains eg gin.
The food was ok, and it looks like Japanese people likes the place. We were the only westeners there.
One odd thing is that you aren't allowed to wear shoes inside the restaurant.