The Okumusashi Green Line 32km Mountain Pass Run is a modest training run in Hanno, Saitama, for runners with established endurance. It follows a 32km mountain-road course from Agano Station toward Seibu-Chichibu Station. The pace and distance are suitable for those who can run a half marathon in about 2:10 or a full marathon in 4:30. Emi Running Club uses it as a leg-strength workout, with a practical format: mountain pass running followed by hot springs and a meal.
The route utilizes the Okumusashi Green Line, a path the organizer, Honami, ran as a student. The first stop is approximately 4km in, after the steepest ascent, featuring the course's sole vending machine. Later stops include a restroom around 11km and Kenmin no Mori near the summit. After Kenmin no Mori, about 10km of downhill remains before reaching the hot spring, which participants note can be challenging for tired legs. Past runners frequently mention cool mountain air, shade, ample rest stops, and a welcoming group atmosphere. However, the required gear list indicates it is a serious event: participants must carry their own water, food, change of clothes, and money, while ensuring their backpack is light enough for the run to the bathhouse.