Mitsubishi Estate is one of the three big Japanese real estate companies. Around two thirds of its operating profit comes from leasing office space in Japan, where half of its portfolio is concentrated in the prime Marunouchi/Otemachi district between Tokyo station and the Imperial Palace. Mitsubishi Estate's predecessor originally bought this land from the government in 1890, and the company sees itself as steward of the showcase area's long-term development, rarely if ever selling any properties there.