Sapporo is the largest city on Japan's northern island of Hokkaido, and is known for its winter sports and beer.
Judo, a martial art that emphasizes throws and grappling techniques, was developed in Japan in the late 19th century and has become a popular sport around the world.
The 1995 Tokyo subway sarin gas attack by the Aum Shinrikyo cult shocked Japan and led to increased scrutiny of religious groups.