The Okinawa 100K Ultra Marathon (ๆฒ็ธ100Kใฆใซใใฉใใฉใฝใณ) is Japan's southernmost major ultramarathon and one of the country's most scenic long-distance road races. Held each December on Okinawa's main island, the event showcases the prefecture's warm subtropical climate, spectacular coastline, and renowned island hospitality. Unlike many ultramarathons that traverse remote mountain trails, the Okinawa 100K follows a picturesque road course through coastal communities, allowing runners to experience the turquoise waters, white-sand beaches, and vibrant culture that make Okinawa one of Japan's premier travel destinations. The event has grown into an internationally recognized ultramarathon, attracting participants from across Japan and around the world who are eager to combine an endurance challenge with an unforgettable island adventure.
The flagship 100K race begins before sunrise in Yonabaru Town and follows an out-and-back route along Okinawa's southern coastline to Itoman City Hall, passing through Nanjo City and Yaese Town before returning to the finish at Yonakohama Park. Along the way, runners are treated to breathtaking views of Hyakuna Beach, Ojima Island, and the crystal-clear waters of the Pacific Ocean. One of the course's defining highlights is the crossing of the spectacular Nirai Kanai Bridge, whose sweeping panoramic views have become synonymous with the event. For those looking to build toward the full ultra distance, the race also offers 50K and 22.5K Nirai-kanai Run & Walk events, making the weekend accessible to both seasoned ultrarunners and newcomers seeking their first long-distance challenge.
