Not a link, but there are many lines that do this; the poster mentions Toyoko line, which (as of now) goes Hannō > Kotake-Mukaihara: Seibu Ikebukuro Line Kota

Not a link, but there are many lines that do this; the poster mentions Toyoko line, which (as of now) goes Hannō > Kotake-Mukaihara: Seibu Ikebukuro Line Kotake-Mukaihara > Shibuya: Tokyo Metro Fukutoshin Line Shibuya > Yokohama: Tokyu Toyoko Line Yokohama > Motomachi-Chūkagai: Minatomirai Line Those are all different companies operating on the same rights of way seamlessly! When you reach the through service stops, it just looks like any normal stop - there is generally no interruption in service, it just stops for some seconds and proceeds onwards like nothing happened. If you visit Tokyo you would notice that sometimes you'll see Tokyo Metro-branded trains on JR tracks, or Toei-branded trains on Keio tracks, and so on. Many lines are like this; if you look up any of the central railway lines in Tokyo on Wikipedia, you'll see on their station charts notes about their through services. Some more instances: Odakyu Line > Tokyo Metro Chiyoda Line > JR Joban line Keio Line > Keio New Line > Toei Shinjuku Line Tokyo Metro Hibiya Line > Tobu Skytree Line > Tobu Nikko Line JR Chuo Sobu Line > Tokyo Metro Tozai Line > Tōyō Rapid Railway Line, and so on.