Complex sentence: From 1933 onward tournaments were held almost exclusively in the "Ryōgoku Kokugikan" until the American occupation forces appropriated it and the tournaments were moved to Meiji Shrine until the 1950s when an alternate location, the Kuramae Kokugikan which was near Ryōgoku, was built for sumo.
Split into simpler sentences: From 1933 onward tournaments were held almost exclusively in the "Ryōgoku Kokugikan" until the American occupation forces appropriated it and the tournaments were moved to Meiji Shrine until the 1950s. Then an alternate location, the Kuramae Kokugikan which was near Ryōgoku, was built for sumo.