The Hidden (Danger) Road to Mt Kobushi

Mountains: Mt. Tosaka (Mt. Keikan) 鶏冠山, Mt. Tokusa 木賊山, Mt. Kobushi 甲武信ヶ岳

Access: Nishizawa Keikoku Parking

In early September 2023, I went on what was supposed to be a fun day adventure with my hiking Sensei, Mr. Kikuchi. The goal was to climb one of Japan's 100 famous mountains, Mt Kobushi. However, we would take a lesser known and more challenging approach to the summit - Mt. Tosaka. Whereas the standard trail is about 4 hours climb, it was said this variation course was more steep and would take approximately 5.5 hours to reach the summit of Mt Kobushi - but in fact, that didn't end up being the case.

We needed to start very early in order to make this a day trip. So, Mr. Kikuchi picked me up at the 7-11 near my apartment around 3:30am. After taking the empty back-roads, we arrived at the trailhead parking by around 6 o'clock in the morning. It was from here that we started the journey. It had been an exceptionally hot September, but that day the temperature had dropped significantly, and so it was still very brisk outside. We both knew however that as soon as we got the blood pumping up those steep hills, we'd warm up in no time. After crossing the a small bridge over the Nishizawa Gorge, we started the course. The beginning of the trail forks in two, and the route we chose ended up being an unnecessarily steep route over a hill only for us to descend back down towards the river. Along the way, we startled some campers who were probably not expecting anyone on this optional trail at that time. A few moments later we ended up alongside the Fuefuki River again, and realized there was no choice but to cross it. Naoyasu was able to quickly hop over the stones, but I had a bit more trouble. But I was able to make it across with no problem. We then climbed up some ropes over a rocky waterfall, and from there we began to ascend Mt. Tosaka's steep ridge.

Despite being a very steep uphill climb, it was nothing I hadn't experienced before. Similar to the Shoulder Ridge towards Mt. Shiroiwa/Kumotori or Mt Myogi's Taruwaki Trail. However, a good hour or so after climbing up the path, the rocky sections started to get more tricky, with several very steep rope sections with lots of grabbing onto rocks and tree roots for support. The course finally flattened out for a little bit at the "gap/col" below the first rock peak. Shortly after, we had finally arrived at the chain section.

I soon realized that the main difference between here and other chain walls like Myogi or Tsurugidake was that the individual chain links were too small to connect to my carabiner/harness, essentially making them completely useless. So, I had to rely on my grip with no extra safety net. I had trust in my strength and as long as I follow the 3 point contact rule, I felt it would be manageable. Naoyasu quickly climbed up the chain without much difficulty, I followed shortly after. All was going well until about 2/3rds to the top. I grabbed a rock for grip, which ended up being loose and almost caused a chain of rocks to fall. I quickly pushed the rock back, and then climbed around the side to get out of the path of danger in case it gave way. I then made my way to the top of the rock, with my heart beating a mile a minute. I knew at this point, there was no turning back, as it would be far too unstable to climb back down this way.

We continued over the rocky and exposed traverse, hitting two more chain sections, although much easier and more stable than the first one. We took a detour path around the final rock peak before finally reaching the summit of Mt. Tosaka. At this point Naoyasu realized that we were not going to reach the top of Mt.Kobushi in time, and suggested I stay at the cabin and descend the next morning. But first, we still needed to get back on the main trail. The next challenge was long, steep, and wild forest trail. It was extremely easy to get lost here, and we had to keep a strong eye out for the little pink ribbon trail markers. There was one point we ended up 10 minutes down the wrong side of the trail and had to do some difficult back-peddling. This trail just went on and on, and really wore us down. Naoyasu stayed far ahead, but we could still yell to each other making sure we were both still on the right path.

The combination of exhaustion, dehydration, and anxiety - there was also pressure to get back to the normal trail before dark with the fear of getting lost. All this stress eventually triggered some significant stomach and head pains. Over the next few months this got worse and worse, and by late October had developed into a stomach ulcer and infection. Thinking back, I believe the stress of this dire scenario is what triggered such health problems. Thankfully, I eventually recovered, although it put me out of commission for a few months.

Our original, misguided schedule had us arriving at the Kobushi Hut by 11:30am, but in reality, I didn't arrive until about half past 4 in the afternoon. Naoyasu was already waiting, and had booked us a space for the night. Since the summit was only 15 minutes away, I went up there by myself (Naoyasu had already been many times before and preferred to rest). At the top, I caputered some beautiful views of the mountain range, the full moon, and even Mt. Fuji. I quickly returned to the cabin to grab some curry and rice dinner. Naoyasu was already out like a light before even 6pm. I stayed up another hour to talk to the staff and a couple other hikers. So, what was supposed to be a simple day hike turned into a 2 day dramatic journey.

Summit of Mt. Kobushi

We got up before sunrise the next morning, and departed the cabin before the crack of dawn.

Naoyasu was again moving at a very steady pace (possibly a subtle reminder for me not to doddle, since we both had work that day). Since he was a bit ahead of me, he told some early morning hikers not to panic when they see bigfoot rushing down the mountainside, confusing hikers until they encountered me.

We made it back to the parking lot and immediately headed back towards Tokyo. Since my job was remote work, I actually took a conference call in the car, and was dropped off at a cafe near Hachioji station to continue the meeting while Naoyasu drove to his work. Some people complain about tough commutes to work, but they've probably never had to race a vertical kilometre down a mountainside to do so.

Check out the full adventure Video on YOUTUBE