Tokyo's trains have some of the best signage in the world. Nearly all the ones in Tokyo and other major cities have English directions. All the stations have color coded numbers like G12 or N13 if Japanese names are hard for you.
Signs on the tracks tell you what station you're at, what the previous station was and what the next station will be.
Every exit has a number and signs on the walls and ceilings tell you which way you need to walk to get to your destination or transfer.
At the gates there are always maps of the area on the walls to lookup where to go if you don't have a smartphone.
I've been all over the world and I can't think of another transit system that has all of those features. Others are always missing one or more.
As for the person below that mentioned they got help in Ikebukuro station, it's great they got help, but I suspect in their panic they didn't notice all the signs. There is no exit from the JR lines that does not have clear signage to every other line (tobu, seibu Ikebukuro, fukutoshinsen, Marunouchi, Yurakucho, ...)