12th FunTrails Round Chichibu & Okumusashi 100MILE/100K/50K 2026

The 12th FunTrails Round Chichibu & Okumusashi brings a demanding weekend of mountain running to Saitama Prefecture on 14–15 November 2026. Its three race labels, FTR100MILE, FTR100K and FTR50K, refer to courses of approximately 160 km, 105 km and 54 km respectively. All three start and finish at Hitsujiyama Park in Chichibu, then explore the steep, repeatedly rising and falling trails of Chichibu and Oku-Musashi, including forest paths and areas around temples and shrines.

Course and challenge

The flagship 100-mile race has approximately 9,722 metres of accumulated ascent, with around 80% of the route on trails. The 105 km course climbs approximately 6,831 metres, also with around 80% trail running. The shorter 54 km race still packs in approximately 2,985 metres of ascent, with around 70% off-road terrain. This is a mountain endurance challenge rather than a flat road ultra: runners should prepare for technical footing, long climbs, descents, darkness and variable mid-November conditions.

Both longer distances start at 06:00 JST on Saturday 14 November and have a 32-hour overall time limit, ending at 14:00 on Sunday. The 54 km race starts at 09:00 Saturday and has a 12-hour limit, finishing by 21:00. Intermediate checkpoints apply, and runners need to manage time at aid stations rather than assuming the final cut-off is the only restriction. The 100-mile race offers a separately registered pacer arrangement for an eligible portion of the course.

Entry and preparation

Published standard entry fees are JPY 45,000 for 100 miles, JPY 33,000 for FTR100K and JPY 16,500 for FTR50K. Student discounts apply to specified age groups, subject to proof of enrolment. Published capacities are 100, 600 and 900 participants respectively. Registration was advertised through RUNNET from 1 May to 29 September 2026, or earlier if filled, so the normal entry window has passed. The longer races require appropriate previous racing experience; check the organiser's final eligibility and mandatory-kit rules.

The event provides aid stations and checkpoint controls along its courses. Runners should study the final route, compulsory equipment, lighting and weather protection requirements, and arrangements for any drop bags before travelling. The published participant check-in is at Hitsujiyama Park on Friday 13 November, 14:00–19:00; the 54 km category additionally permits Saturday 14 November, 06:30–08:30 check-in. Do not assume same-day check-in is available for the longer races.

Getting there

Hitsujiyama Park is roughly a 15–20-minute walk from Seibu-Chichibu Station. The Seibu railway connection from Tokyo's Ikebukuro area makes Chichibu accessible by public transport, although runners tackling the early start or overnight finish should plan accommodation and return journeys carefully. The saved map pin identifies the park as a whole, not a surveyed starting gantry.