Of course, taxi drivers know where the train station, major hotels, or other attractions are located. Unfortunately, tourists often don't know which famous landmark the restaurant they want to visit is nearby. However, Japanese taxi drivers are fundamentally honest and won't rip you off. If they can't find the address, they will drive to the nearest Koban in the desired district and ask for directions. A "Koban" is a small police station. These can be found in every district, often no larger than a kiosk. Here, there is a detailed map of the district where the police box is located.
In Tokyo (and in our experience, also in other Japanese cities), it is additionally challenging that only the larger streets have names. Finding something is a challenge even for a pathfinder with a compass, because there are thousands of tiny alleys in Tokyo, none of which are marked with names on street maps. We often searched for a restaurant described in the travel guide and gave up in frustration despite having a map. Additionally, restaurant names typically include Kanji characters, which are wonderfully decipherable in the printed travel guide, but have little to do with the signs in the real world, as they have been "enhanced" for design purposes.