Ultra Running Hub Shimanto, Kochi Pref., Japan · Sunday, October 18, 2026
River Shimanto 100km
What the course asks
DUV results for the 2025 edition (100km) — finishers only. Starters are not published, so the field was at least this big and no finish rate can be given.
Typical conditions, October
Regional 2001-2020 average for October — NASA POWER, grid elevation 112 m. Not a forecast.
Results history
| Year | Race | Finishers | Men's winner | Women's winner |
|---|---|---|---|---|
| 2025 | 100km | 1,008 | Tatsuya Itagaki · 06:49:18 | Haruna Takano · 07:47:12 |
| 2024 | 100km | 1,220 | Ryo Obayashi · 07:09:06 | Miho Nakata · 07:39:51 |
| 2023 | 100km | 1,078 | Toshiki Takenaka · 06:52:26 | Miho Nakata · 08:01:00 |
| 2019 | 100km | 1,282 | Yoshiki Kawauchi · 06:48:46 | Miho Nakata · 07:52:20 |
| 2018 | 100km | 1,354 | Ryo Obayashi · 06:52:15 | Aiko Kanematsu · 08:03:15 |
| 2017 | 100km | 1,408 | Yoshiki Kawauchi · 06:42:04 | Aiko Kanematsu · 08:05:37 |
| 2016 | 100km | 1,365 | Ryo Obayashi · 06:55:43 | Miyuki Yamaguchi · 08:19:48 |
| 2015 | 100km | 1,246 | Yoshikazu Hara · 06:52:52 | Miyuki Yamaguchi · 08:19:25 |
| 2014 | 100km | 1,246 | Yoshikazu Hara · 06:43:23 | Hisayo Kakinuma · 08:47:48 |
| 2013 | 100km | 1,088 | Yoshikazu Hara · 06:48:44 | Tomoko Hara · 08:04:39 |
The field shrank 17% between 2024 (1,220) and 2025 (1,008). 18% of the 2025 field were women.
DUV results for the 2025 edition (100km) — finishers only. Starters are not published, so the field was at least this big and no finish rate can be given.
Course notes
- terrain This is a fast & flat course. Expect fast, runnable sections where rhythm is key.
- gear With trail terrain, choose a shoe with moderate cushioning for optimal performance.
- nutrition For 100km+ efforts, prioritize real food at aid stations to prevent palate fatigue.
Gear for this race
Chosen for 100 km of trail with 700 m of ascent.
- Trail Running Shoes 100 km of trail — cushioning that is still there in the last quarter.
- Race Nutrition Past 100 km the palate quits before the legs do — carry more than one flavour.
- Hydration Vests Flask capacity for 100 km, without the bounce.
- Headlamps A 14 h limit puts you out there after dark.
- Accessories Chafe and blisters end more 100 km races than fitness does.
Overview
River Shimanto 100km takes place in Shimanto, Kochi Pref., Japan, featuring a road race that draws a massive turnout, with a field bigger than 97% of 100k races and smaller than 3%. The 14-hour time limit demands an average pace of 8.4 minutes per kilometer, establishing a standard tighter than 81% of 100k cut-offs and more generous than 19%.
The route gains 700 meters across 100 kilometers—averaging 7 meters of climb per kilometer—with the opening 20 kilometers climbing steadily from 0 to 650 meters above sea level before settling into a large loop along the Shimanto River from Warabioka Junior High School to Kochi Kenritsu Nakamura High School. Managing effort through that front-loaded ascent leaves a faster second half to stay ahead of the restrictive cut-off.
Similar races
Other 100K trail ultras, closest in distance first.