My Onsen Experience - Bathing With 20 Japanese Men

The Japanese onsen is something reported by many travel sites as a cant miss experience.  Many of the more popular spas, powered by incredibly hot spring water, are located in the mountaneous regions of the country.  Because of this they are highly regarded not just for their therapuetic values, but for the beauty which the onsen is built around.  (Photo "Japanese Macaques" by Yosemite)
To me, this sounded like a great experience and something I absolutely had to try.  So when I made it to Nikko shortly after my arrival to the country, I knew I had to check one out.
A friend I made shortly after arriving to the city suggested a trip to the Yashio Spa Onsen outside of Nikko for a day trip.  We set out on a 90 minute walk from the city to one of the closer spas, not really sure where we were going and hoping we'd actually make it in a reasonable period of time.  Along the way we encountered a number of detours such as a self-immolation graveyard, a burial site for people who committed suicide by setting themselves on fire, and nearby Jako Falls.
It seemed like a good idea at the time to head to the waterfall, but when the 90 minute trip turned in to a 3 hour hike after a long winding uphill side trip to the falls, we really were looking forward to the onsen. Considering most people only go to Nikko as a day trip from Tokyo to see the famous shrines and Hear No Evil, See No Evil, Speak No Evil monkeys, we were already outside of the traditional path that the vast majority take.
What happened next put me even further out of my comfort zone, especially when considering this was the second stop of my entire 5 month journey.
Once we arrived, the onsen was most welcoming on our sore bodies.  The experience was a relatively affordable 500 yen for unlimited use, plus 250 for a small towel and 100 for locker rental (~$10 total). The euphoria of a cheap deal lasted only a brief while until one of the workers uttered a frightening phrase:  No swim suits allowed.
Surrounded by 20 old Japanese men I let go of all my shame and entered the bath house. The fear was quickly eliminated as no one seems to care that everyone is minus all clothes except for a 3 ft by 1 ft towel that doesnt quite cover all.  The spa itself was most rewarding as three different spas, including one located outside, felt most amazing even when the feed water was a scorching 40°C (104°F).  The sauna was even more hot at an ambient tempurature of 57°C (135°F).
Sweaty, but satisfying.
For me, the experience was priceless and made the preceding 3 hour hike well worth it. After all the excitement and fear, and since you cannot take pictures inside the onsen's for obvious reasons, I now have an incredibly tiny towel as proof that, yes, I have no shame.