Since its opening in 1971, Keio Plaza Hotel has been a pioneer in the convention hotel industry, leading Japan's MICE* sector. The stage for many successful international conferences was the Concord Ballroom on the 5th floor of the Main Tower, which was hailed as the “finest in the Orient” at the time.
In addition to its grand 1,320 square meters of space, capable of accommodating conferences with up to 2,000 attendees, the Concord Ballroom was one of the first to be equipped with simultaneous interpretation equipment for six languages (United Nations style), television broadcast facilities, and seating for members of the press. The lighting and sound systems, which utilized the latest technology at the time, have beautifully and memorably enhanced the atmosphere of the many events held there. Shortly after opening, the hotel was the first in Japan to successfully host the “World Conference of Major Cities.” In the following years, during large conventions held by American corporations, there were even 12 occasions where guests arrived in groups of 500 by jumbo jet. In the 1980s, the hotel took the lead in making its facilities barrier-free, starting with events such as the “International Conference on Social Welfare” and the “World Congress on Rehabilitation” in 1988. In 2001, the entire hotel was equipped with fiber optic cables, leading to an increase in IT-related international conferences being held at the venue.
During the major renovation in 2008, the Concord Ballroom was further enhanced in elegance and modernity. Its history is intertwined with the history of various international conferences in fields such as cutting-edge technology, advanced medicine, and continuously evolving IT. It can be said that the ballroom has witnessed many groundbreaking discussions throughout the years.
Today, the carpet design in the Concord Ballroom features the theme of water ripples. This symbolizes the venue's achievements and pride in creating “waves of progress” in the MICE industry, as well as the hopes and expectations for the future.
*MICE is an acronym for Meetings, Incentives, Conventions, and Exhibitions/Events. It refers to a broad range of business events aimed at academic research and industry development.

