Name: Shimanto River Ultra Marathon Online Challenge [Training 1 Month 100km] (四万十川ウルトラマラソン オンラインチャレンジ【Training 1month 100km】)
Start: 2026-09-01
End: 2026-09-01

About the Event

Immerse yourself in the tranquility of Japan's last clear river, the Shikoku River, as you embark on an unforgettable journey with the Four Million Ten Ultra Marathon. Whether you're a seasoned ultramarathon runner or have long admired this race from afar, we invite you to join us for an experience that combines breathtaking scenery and local culture.
The event offers several participation packages designed to cater to your preferences while ensuring everyone receives a high-quality T-shirt as part of their entry fee. For those looking for something more, there are additional options such as traditional udon noodles or long-sleeve shirts at 6,990 yen. For the ultimate experience, you can opt for grilled bonito fish from one line fishing, along with either a cap, pants, or a hoodie priced at 8,990 yen. The most luxurious package includes premium beef (for sukiyaki or yakiniku) or eel, paired with an original set of apparel including a cap, long-sleeve shirt, pants, and hoodie for 12,990 yen.
As you traverse the picturesque Shikoku River valley, expect to be greeted by lush greenery, serene landscapes, and friendly locals who take pride in showcasing their unique culture. This race is not just about crossing the finish line; it's an adventure into a region that has preserved its natural beauty and traditional ways of life.
Join us at the Four Million Ten Ultra Marathon for a memorable run through one of Japan’s most pristine environments.

Races Offered

November Run 1month 100km

Sep 01, 2026

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Distance — 100K

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Type — Running

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21 days remaining

October Run 1month 100km

Sep 01, 2026

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Distance — 100K

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Type — Running

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21 days remaining

Training 1month 100km

Sep 01, 2026

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Distance — 100K

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Type — Running

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21 days remaining

Year-end 1month 100km

Sep 01, 2026

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Distance — 100K

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Type — Running

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21 days remaining

２month 100km Stage 1

Sep 01, 2026

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Distance — 100K

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Type — Running

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21 days remaining

２month 100km Stage 2

Sep 01, 2026

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Distance — 100K

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Type — Running

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21 days remaining

３month 100km

Sep 01, 2026

straighten

Distance — 100K

terrain

Type — Running

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21 days remaining

Weather History

These values represent the 3-year monthly averages for September in .

thermostat Temperature

16.7° / 23.6°

wb_sunny Feels like

17.9° / 25.0°

light_mode Avg sunshine hours

8h 44m

water_drop Avg rainfall

5.7 mm

ac_unit Avg snowfall

—

air Avg wind speed

4.7 km/h (Light breeze)

opacity Sweat loss rate

High

terrain Course conditions

Hard and dry surface

sunny Max UV Index

Moderate (5.0)

humidity_mid Humidity

86.6%

wb_twilight Sunrise

05:25

nightlight Sunset

17:50

Hotels & Places to Stay

Runner Reviews

Read what other athletes have to say about their experience at the Shimanto River Ultra Marathon Online Challenge [Training 1 Month 100km] (四万十川ウルトラマラソンオンラインチャレンジ【Training 1month 100km】).

★ ★ ★ ★ ★