第100回・赤羽トライアル（5km/10km/15km/HALF/30km/フルの部）

From Akabane Station or Akabane-Iwabuchi Station, this race leads to the Arakawa Riverbed Course with a straightforward "Flat course!" The 100th Akabane Trial offers a repeatable river path effort, suitable for a check-in rather than a major event. It is designed as a fun run, so the atmosphere will be practical rather than overly formal. The course is a short riverbed loop, providing steady footing, easy pacing, and minimal complexity: settle in, manage the wind, and run your pace. The field is expected to include fun run participants as well as those using the flat layout for a controlled effort. The unique features are practical: a "Stamp card gift," where "Collect 3 to get 1 race free," and the nearby public bath "Otamayu" is available for participants afterward.