Although it is easy to find your way to the destination using your smartphone, it is quite complicated when you are taking a subway in Tokyo. At first you have to get out from the station. Then, you have to check the way to the destination.
However, subway stations in Japan are equipped with maps and also the exits, the way to the streets are numbered. Then, major places including hotels are mentioned on the map and therefore you can find your way before going up to the street. It is convenient if the exits are numbered or have specific names.
When you check your destination on website prior to your visit, you can find the nearest station and also the which exit to take. Therefore, you have to remember the station and also the exit.