The Asakusa Line was the first subway line in Japan to offer through services with a private railway. Today, it has more through services to other lines than any other subway line in Tokyo. Keikyu operates through trains on the Keikyu Main Line to and the Keikyu Airport Line to . The Keisei Electric Railway operates through trains on the Keisei Oshiage Line to and the Keisei Main Line to , and the Shibayama Railway runs trains via the Keisei Main Line and the Shibayama Railway Line to . Via its through services with Keisei and Keikyu, the Asakusa line is the only train line that offers a direct connection between Tokyo's two main airports.