On Saturday, July 4, 2026, Seibuen Amusement Park in Tokorozawa, Saitama Prefecture, closed to regular visitors for a full private rental, hosting the Toshin Partners Team Ken's Cup Aquathlon at Seibuen Amusement Park. Real estate investment company Toshin Partners served as special sponsor for the race, an aquathlon that remains uncommon this close to central Tokyo. Athletes and their families gathered again this year for a day full of smiles and cheers.
Five Highlights of the Race
1. A Rare "Aquathlon" Race Near Central Tokyo
Aquathlon, a swim-and-run event that removes the cycling leg from triathlon, needs no bike gear, making it accessible for kids and adults alike. Opportunities to compete in one are limited, and this race has drawn attention as one of the few aquathlon events held in the greater Tokyo area.
2. Seibuen Amusement Park Rented Out in Its Entirety
The venue for the race was the amusement park itself, rented out completely. Competitors swam and ran through the park's pool and running course, an unusual, out-of-the-ordinary setting that's the event's biggest draw.
3. A Parent-and-Child Run for Racing Together
The race included a "parent-and-child run," where children cross the finish line together with a parent. It's a category families have come to enjoy every year, offering a chance to build bonds through sport.
4. Wooden Medals Await Finishers
Rather than mass-produced metal medals, finishers were presented with warm wooden medals at the awards ceremony — one-of-a-kind keepsakes recognizing each finisher's effort.
5. Organized by Triathlon Team Toshin Partners Team Ken's
The race was organized by Toshin Partners Team Ken's, a triathlon team that has trained numerous athletes. Its experienced staff earned high trust from racers and families by running a safe, well-managed event.
Event Overview
- Event name: Toshin Partners Team Ken's Cup Aquathlon at Seibuen Amusement Park
- Date: Saturday, July 4, 2026
- Venue: Seibuen Amusement Park (private rental)
- Event type: Aquathlon (swim + run)
- Categories: General, Kids, Parent-and-child pairs
- Support: Tokorozawa City, Tokorozawa City Board of Education
- Organizer: Toshin Partners Team Ken's
- Special sponsor: Toshin Partners
Results
| Entries | 413 |
| Starters | 401 |
| Finishers | 394 |
| Finish rate | 98.3% |
Conditions on race day: Temperature 22.1°C, water temperature 23.0°C, WBGT 21.3°C.
The race wrapped up without incident, with a completion rate of 98.3%. From setup through race operations and teardown, staff coordination stood out, creating an environment where racers could focus on competing with peace of mind.
Toshin Partners' Long-Running Support for Team Ken's
Toshin Partners has sponsored Toshin Partners Team Ken's, the team organizing this race, for many years. The company says it will continue contributing to the growth of sport in the local community and to creating spaces where people of all ages can enjoy sports.
