Question: The largest mixed martial arts organization in the world held and event in what Japanese city on April 14, 2000?
Context: Shooto is a combat sport/mixed martial arts system and mixed martial arts organization that is governed by the "Shooto Association" and the "International Shooto Commission".  Shooto was originally formed in 1985, as an organization and as a particular fighting system derived from shoot wrestling.  Practitioners are referred to as shooters, similarly to practitioners of shoot wrestling.  Shooto rules have evolved such that their events are now true mixed martial arts competitions. The Ultimate Fighting Championship (UFC) is an American mixed martial arts organization based in Las Vegas, Nevada, that is owned and operated by parent company WME–IMG.  It is the largest MMA promotion in the world and features the top-ranked fighters of the sport.  Based in the United States, the UFC produces events worldwide that showcase eleven weight divisions and abide by the Unified Rules of Mixed Martial Arts.  As of 2017, the UFC has held over 400 events.  Dana White serves as the president of the UFC.  He has held that position since 2001; while under the leadership of Dana White the UFC has grown into a globally popular multibillion-dollar enterprise. The Warrior Xtreme Cagefighting (WXC) is the largest mixed martial arts (MMA) promotion company in Michigan that hosts most of the top-ranked fighters in the state and is looking in 2017 to produce events Nationwide.  Based in the United States, the WXC has eight weight divisions and enforces the Unified Rules of Mixed Martial Arts.  Norbert Pasztor serves as the president of the WXC. EliteXC: Destiny was the inaugural mixed martial arts event by the mixed martial arts organization EliteXC.  The event took place on Saturday, February 10, 2007 at the DeSoto Civic Center in Southaven, Mississippi.  The main card aired on Showtime, with the undercard was streamed live on the Proelite.com website. Respect Fighting Championship (RESPECT.FC) is a mixed martial arts organization in Germany.  It has won the GNP Award for the best German promotion in 2009, 2010 and 2011 Especially noteworthy in this context is that RESPECT.FC has beaten the Ultimate Fighting Championship (the biggest mixed martial arts organization in the world), who was nominated with their first German based event UFC 99.  The events are broadcast by Fightcast.tv, the only HD Fightsport portal in Europe. UFC 25: Ultimate Japan 3 was a mixed martial arts event held by the Ultimate Fighting Championship on April 14, 2000 at the Yoyogi National Gymnasium in Tokyo, Japan. Desert Force Championship (DFC) is the largest mixed martial arts promotion company in the Arab World, which hosts most of the top-ranked Arab MMA fighters in the region.  The championship has held ten televised events and presided over approximately 100 matches.  DFC currently airs on MBC Action on a bi-monthly basis.  In 2010 Desert Force launched the “Elimination Series”, a single-elimination tournament for Arab MMA fighters competing to become the first regional MMA title belt holders in 7 respective weight classes.  Fighters from across the Middle East have competed in 7 weight classes, namely Bantamweights, Featherweights, Lightweights, Welterweights, Middleweights, Light-Heavyweights and Heavyweights; each class enforcing the Unified Rules of Mixed Martial Arts.  Participating countries include: KSA, United Arab Emirates, Qatar, Kuwait, Jordan, Iraq, Bahrain, Palestine, Syria, Lebanon, Egypt, Morocco, Tunisia.  In recent years DFC fights have been officially refereed by MMA referee Yves Lavigne. Eddy Bengtsson (born April 30, 1979, in Gothenburg) is a Swedish retired wrestler who competed in the Men's Greco-Roman 120 kg at the 2004 Summer Olympics and 2000 Summer Olympics.  Bengtsson retired from wrestling and competed in many grappling tournaments, and also in mixed martial arts competition.  On April 23, 2010, he faced Alexander Emelianenko for the Russian-based Pro FC mixed martial arts organization losing by KO in the opening round.  Bengtsson made a brief comeback as a wrestler to try to reach the 2012 Summer Olympics but failed, On May 10, 2012, he officially announced his retirement as a wrestler. Hatsu Hioki (日沖発 , Hioki Hatsu ) (] , born July 18, 1983) is a Japanese professional mixed martial artist competing in the featherweight division.  He is the former Shooto Lightweight Champion, Sengoku Featherweight Champion, and TKO Featherweight Champion.  Hioki is a long time Shooto veteran and has fought most of his fights in Japanese promotions including the largest Mixed Martial Arts organization at the time, Pride Fighting Championships. Enson Inoue (Japanese: エンセン井上 , born April 15, 1967) is a Japanese-American retired mixed martial artist.  He has a professional MMA record of 12-8.  He is a former Shooto Heavyweight Champion.  He had also previously fought in Pride Fighting Championships, one of the biggest mixed martial arts organization at the time.  Inoue was featured in the documentary film "Rites of Passage: The Rebirth of Combat Sports".  He also appeared in the martial arts movie "Redbelt".
Answer: Tokyo, Japan