Lake Saroma 100K Online Challenge Japan 2026: October 1-Month

Lake Saroma's October 1-Month Online Challenge is a dedicated one-month virtual 100 km round in the 2026 Saroma online programme. It is separate from the November 1-Month and November-December Stage 2 challenges already listed in ARC.

Accumulate 100 km during October

Complete at least 100 km between 1 and 31 October 2026 using TATTA. The challenge is cumulative, so the total may be built across multiple eligible runs rather than completed in one continuous effort.

Participants must live in Japan and use a compatible smartphone with TATTA. Registration and TATTA must use the same RUNNET account. Manual distance entry is generally not accepted.

Registration status

Registration ran from 7 August through 25 September 2026 and is now closed. This listing is for participants already entered and completing the currently active October challenge.

Completion and entitlements

RUNNET publishes four package prices: JPY4,990, JPY6,990, JPY8,990 and JPY12,990. The official event information confirms an original event T-shirt or sleeveless top as the participation item and a finisher medal for verified finishers.

The package selected determines additional participation rewards. Because the public October page reviewed does not expose every package's exact alternative item in text, ARC does not copy package-specific extras from another Saroma round without verification.

Credibility

The challenge is organised by R-bies Sports Foundation and registered directly through RUNNET, with the official Saroma online site linked from RUNNET. This is a strong institutional organiser and registration chain.