Mt. Kobushi is a pointy peak straddling the border of Yamanashi and Saitama prefectures. The views out to Mt. Fuji are superb and the fall colors breathtaking.
From the southern exit of Enzan station (塩山駅), take a bus bound for Nishizawa-keikoku iriguchi (西沢渓谷入口) and get off at the last stop. Alternatively, you can do this hike as a 2 night, 3-day trek from Mt. Mizugaki.
From the bus stop, hike up the road towards Nishizawa gorge. The trailhead will be on the right side of the road after about 20 minutes or so. You’ve got 2 trail options. One is signposted on the right, while the other is behind the creepy-looking Nishizawa hut (西沢山荘) a little further along the road. Take your pick, as both trails meet up along the way. I’ve been told that the one behind the hut, called “Tokuchan” path (徳ちゃん新道), is more commonly used, and that’s the one I used. The trail wastes no time in climbing through a cedar forest. After about 2-1/2 hours of steep climbing, you’ll come to a trail junction (the meeting of the 2 paths I mentioned earlier). Take a break here, and get ready for 600 more meters of vertical altitude gain. It’ll take another 2 hours of tough slogging to reach the saddle and junction just below the summit of Mt. Tokusa (木賊山). The trail to the right will lead to Mt. Hafu (破風山), but ignore this trail and head left to Mt. Kobushi. After reaching the summit of Mt. Tokusa, the trail drops steeply to a saddle between the 2 peaks. There’s a nice hut here awaiting you, with a camping area and water source. Consider staying here to break this hike up into a more leisurely 2-day trek. From the hut, it’s a steep, 20-minute hike to the summit of Kobushi. If the weather is good, you’ll have an awesome view of Mt. Fuji directly in front of you, as well as the Minami, Chuo, and Kita Alps, Yatsu-ga-take, Mt. Asama, and all of the peaks of Chichibu-Tama-Kai National Park. Either retrace your steps back to the hut, or continue on the trail from the summit over to Jumonji-toge (十文字峠), where you’ll find another hut and an alternative way off the mountain. Nishizawa gorge, at the start of the hike, is worthy of a side trip if you’ve got extra time/energy either before or after the hike.
The Outdoor Type ebook Sydney Outdoor Adventures has information on a whole range of outdoor activities in Sydney, from great surf beaches, hikes, mountain biking trails to camping spots, parks and reserves and diving locations. See here for more information.