The Japan Open is a men's tennis tournament held in Ariake Tennis Forest Park with its center court Ariake Coliseum, located in Koto, Tokyo. The historical precursor event, the All-Japan Championships was founded in 1915, then later became the Japan International Championships. In 2018, the venue switched to the Musashino Forest Sports Plaza as the Ariake Coliseum was renovated for the tennis events at the 2020 Summer Olympics. The championship includes men's singles and doubles competitions.