vAfter checking in, I made my way a few doors down to the local community center, where I changed into a black outfit and joined a small group of other would-be ninja for a lesson in the stealthy arts from Matsuhashi-san, a local ninja expert and by day the manager of a souvenir store in front of Chusha Shrine.

Known as experts in espionage and guerilla warfare, ninja played an active role in the wars that engulfed Japan for much of its history. Living outside the country's rigid feudal system, they hired themselves out to warring feudal lords, acting as spies, assassins and occasionally even as irregular troops on the battlefield. Often penetrating deep into enemy territory, they would strive to accomplish a given task before melting away unseen, but when threatened could rely on lethal self-defense skills.

"In ninjutsu, techniques are always to defend, never attack", Matsuhashi-san explained. "The goal is always to end the fight as quickly as possible, sometimes even killing the opponent with a single blow."

Founded by the 12th century warrior Nishina Daisuke, the local school of Ninjutsu, called Togakure Ryu, adapted and grew over centuries of conflict to become the country's third most prominent, after the more famous bands from Iga and Koga. At its peak in the Warring States Period, the Togakure Ryu became highly sought after and was said to have served both Takeda Shingen and Uesugi Kenshin - two of the region's most powerful warlords, and lifelong enemies.

After marking the beginning of the lesson with a ritual bow, hand clap and nine-syllable Buddhist chant, Matsuhashi-san and his two companions began by showing us some of the basic postures and movements, beginning with a side-facing stance called ichimonji no kamae.

Although we wouldn't get the opportunity to practice amongst ourselves due to the limitations of social distancing - Matsuhashi san and Yamaguchi san went on to demonstrate a series of painful-looking joint locks, used to quickly subdue an opponent.

For our first hands-on experience, we each took a practice sword and learnt how to perform a series of basic attacks, drawing the sword and cutting vertically, horizontally or diagonally in a single movement called nuki uchi. Balancing precariously in our sideways stance while awkwardly clearing the bade from its scabbard, even the most simple movements could be surprisingly complicated.

After our first wobbly attempts with a sword, we were next introduced to some techniques for a wooden staff of around shoulder height, something typically carried in former times by pilgrims and other travelers on the road. Showing a ninja's ingenuity for turning everyday items into training tools, Matsuhashi-san was today making use of a long, heavy rolling pin used to roll buckweat flour into soba noodles.

Last of all, we had the chance to learn about shuriken - the iconic ninja throwing weapon seen in countless films and anime shows. Matsuhashi-san began by showing us three types - the bo shuriken, resembling a heavy dart and thrown in a straight line, the classic four-pointed throwing star, and lastly a heavier, roughly square shaped plate called a teppan. Unique to the Togakure Ryu, this began as a carpentry tool to extract nails and could be spun through the air at a target or concealed in the hand to use up close.

After a quick demonstration, we took turns throwing shuriken at a wooden target - a particular highlight of the lesson for me, this was especially fun despite some mixed results! With our ninja experience drawing to a close, we repeated the simple ritual of bowing, clapping and chanting a short mantra, and then it was time to head back to the ryokan for a delicious course meal and a long soak.

Making an early start the following morning, I joined a group of other guests in front of a beautifully decorated altar to take part in a session of morning prayers led by Miyazawa-san, the owner of the ryokan. Dressed in flowing green vestments, Miyazawa-san performed a series of chants in a low, measured voice, sometimes rhythmically striking a drum.

At one point, he asked us to bow our heads as he shook an onusa - a ritual object resembling a wand decorated with zigzagging paper streamers. While hard to describe, the ceremony conveyed a strong sense of dignity and purpose, and left us feeling strangely invigorated.

After packing my bags and enjoying a tasty traditional breakfast, I set out to enjoy the surrounding winter landscape on a snowshoeing tour led by two local wildlife guides as well as one of the town's ninja instructors from the previous evening.

The snow had continued to fall and deepen overnight, and conditions looked perfect as we made our way to the start of our trail - the famous avenue of cedars leading to Togakushi's Okusha or inner shrine.

Strapping on snowshoes, we were soon on our way and gliding through thick, powdery snow. As we approached a stately wooden torii gate marking the entrance to the shrine's sacred forest, Yamaguchi-san - our ninja guide - produced a conch shell wrapped in woven cord and blew into it, producing a series of trumpet-like notes.

The conch, he explained, had a special significance to mountain ascetics called shugenja, whose history was intertwined with that of the ninja and had for centuries used this area for spiritual training.

As we continued along the trail, Yoshii-san, one of our wildlife guides, pointed out the great variety of trees and how tall many of them were. While much of the surrounding woods had seen intensive logging, trees within the shrine's limits were considered sacred and left to grow undisturbed, sometimes for hundreds of years.

A little later our second guide, Inoue-san, indicated a carved stone tablet sticking out of the snow beside the path, marking the route taken by a veteran mountain ascetic, who in the 1860s carried a heavy sacred mirror all the way to a shrine at the peak of nearby Mount Takatsuma. Now inhabited by the god of the shrine, the mirror remains there to this day, and at a certain time of day, when conditions are perfect, it is said that light can be seen glinting off its surface from far away.

Further along, we arrived at an avenue of tall cedars leading to the famous Zuishinmon Gate - a beautiful red-painted building with a distinctive thatched roof. As we paused to admire the view, Yamaguchi-san explained that the gate marked a boundary between the shrine's inner and outer precinct. Said to be guarded by the nine-headed dragon Kuzuryu, this inner part had for centuries remained off-limits to all but a select few, giving rise to local legends about what might be hidden inside - a secret source of iron, or water perhaps, or gold hoarded over years of secret missions.

The gate itself, like the inner shrine, began life as Buddhist architecture at a time when Buddhism and Shinto intermingled freely. In the Meiji era, however, the pursuit of national unity led to a policy of enforced separation known as shinbutsu bunri. This would leave an indelible mark on Togakushi, as locals converted to the native Shinto religion and the shrine was stripped of its Buddhist iconography. Inside the gate, two imposing statues of Buddhist gods were replaced with Shinto ones, the originals now standing at Zenkoji Temple in Nagano.

Beyond the gate, the path leads on between rows of even taller cedars, planted four centuries ago by the son of the warlord Uesugi Kenshin. As we looked on, a powerful wind gusted through the trees, filling the air with ice and snow.

Crossing a narrow stream to the right of the path, we made our way into an opening in the forest with Mount Togakushi looming up ahead. The mountain, Yamaguchi-san said, contained as many as 33 hidden caves, used by ascetics over the centuries. Here they would take shelter for days or even weeks at a time while meditating, exercising and subsisting entirely on what meagre plant life they could find. Shugenja, Yamaguchi-san explained, believed that their spiritual power would only increase as their bodies drew closer to death.

As we enjoyed the view, Yamaguchi-san took the opportunity to share some more stick or spear fighting techniques, this time with a modern trekking pole filling in for a traditional pole-arm, and an unusual punch known as bosshi ken, in which the thumb is used to strike at the body's vital points. Then, with a farewell blow of the conch shell, we began a long circuitous route, laughing out loud as we leapt over little streams and into deep snow drifts.

With my time in Togakushi drawing to an end, we retraced our steps to the trailhead. Back in the village, there was just time for a final stop at the Yamaguchi-ya, the restaurant and store owned by our ninja guide, for a hearty plate of cold soba served with grated daikon, tempura and pickles. The buckwheat grown in Togakushi, I learned, is in fact a regional delicacy and used to make soba throughout Japan.

As a place that has lingered on my travel wishlist for too long, it was a genuine delight to finally visit Togakushi at such a spectacular time of year and with so many friendly and knowledgeable guides to enrich the experience. It's a place I would heartily recommend to anyone with an interest in Japan's mountain landscapes, wildlife, or some of the most mysterious aspects of its folk history.

To book your own introductory ninja lesson or snowshoeing tour, please contact the local tourist association or enquire with any local accommodation when making a booking. Snowshoes can be rented from the tourist association and from the Yamaguchi-ya.

From Nagano Bus Terminal, take the number 70 bus (about 70 minutes, fare 2,200 yen, departures every hour).

• Togakushi Tourist Association
• Miyazawa Ryokan
• Yamaguchi-ya