Subways
Clean & efficient
The big cities have subway (chikatetsu) networks that are extremely clean and efficient, though can get very crowded at rush-hour times - think 8 to 9am and just after 5pm.
And yes, you can see guys with white gloves pushing commuters into rush-hour subway carriages on some lines in Tōkyō around 8.30am!
Tōkyō has the most extensive network. You’ll also find subway systems in Kyōto, Osaka, Nagoya, Sapporo and Fukuoka.