Tokyo Metro is a metro system of the Tokyo subway system along with Toei which means operated by the metropolitan government.
The Tokyo Metro Co is a private company which is owned jointly by the Tokyo metropolitan government and the Japanese government respectively. The Toei and Metro trains form separate networks.
The people who use a prepaid rail pass can use both the network systems while regular ticket holders have to purchase a special ticket to change from the Metro line to a Toei line and vice versa.
Ticketing machines give instructions in Japanese as well as English, and the train stops are also announced in both the languages. The stations are also built in a way to help the blind using Braille as their base.
The metro services are extremely punctual and regular, however they do not operate from one to five at night.