Japan Air System Co., Ltd. was the smallest of the big three Japanese airlines. In contrast to JAL and ANA, its international route network was very small, but its domestic network incorporated many smaller airports that were not served by the two larger airlines.
The company was originally formed as Toa Domestic Airlines in a merger between Toa Airways and Japan Domestic Airlines in 1971. In 1988 the current name Japan Air System (JAS) was taken. In 1988 Japan Air System began service from Narita to Seoul, South Korea. In 1995 the airline had 99 domestic routes and some international routes. In 2001, JAS agreed to merge with JAL. In 2002, JAS and JAL established a new holding company which was called Japan Airlines System and they were reborn as the new Japan Airlines (JAL) group. Airplane liveries were changed to match the design of the new JAL group. In 2004, Japan Airlines (old JAL) changed its name to Japan Airlines International and Japan Air System (JAS) changed its name to Japan Airlines Domestic.