Branching out from Karuizawa: 2–3 autumn days through Kusatsu, Asama, and Usui Pass

If you have ever visited Karuizawa in autumn as a “day trip from Tokyo,” you may have felt the same way I did the first time: it is undeniably beautiful—the vivid red leaves around Kumoba Pond, the scent of freshly baked pastries along Kyu-Karuizawa—but somehow, something feels missing. It is like finishing an appetizer only to be told it is time to leave. Karuizawa was never really meant to be a standalone destination. It is a gateway to the entire highland region around Mount Asama, where autumn lasts longer and feels more intense than anywhere you can reach within one hour by Shinkansen from Tokyo.

The best part is that Karuizawa Station lets you branch out in four completely different directions. Head north to Kusatsu Onsen, the steaming hot-spring town reached by a bus route that passes through some of the region’s finest autumn forests; stop midway at Onioshidashi, a sea of volcanic rock beneath Mount Asama; travel east to Yokokawa and the historic railway route over Usui Pass; or continue west by Shinkansen to Nagano and the more-than-1,000-year-old Zenkoji Temple.

In this article, I’ll suggest practical ways to combine these routes into a well-paced 2–3-day autumn trip—what to visit first, where to spend each night, and which stops are truly worth the effort. This is not just a list of destinations, but the actual order I followed and found smooth, with less hauling luggage back and forth.

Why Karuizawa makes the ideal autumn “base”

Karuizawa sits at an elevation of around 1,000 meters, so its leaves change color a full month earlier than Tokyo’s—usually peaking from late October to mid-November, depending on the year. More importantly for planning, it is one of the few transport hubs in the region with a Shinkansen connection (the Hokuriku line, just over 1 hour from Tokyo), mountain buses to Kusatsu, and buses and hiking routes descending toward Yokokawa in Gunma.

That means you can arrive in Karuizawa in the morning, leave your luggage at the station or hotel, spend the whole day exploring, and then head in another direction the next day without returning to Tokyo. During foliage season, not having to go back to Tokyo is a huge advantage: weekend trains and buses are crowded, and every unnecessary backtrack costs half a day of sightseeing.

Another detail that people often overlook is Karuizawa’s wide range of accommodation, from affordable guesthouses near the station to forest resorts. That makes it easy to arrange your first night here. For the second night, I’m going to convince you to stay in Kusatsu—the reason comes below.

Four nearby routes worth combining with Karuizawa

Kusatsu Onsen — the most rewarding mountain bus ride of foliage season

Kusakaru Kotsu operates a direct bus from Karuizawa Station to Kusatsu Onsen, taking around an hour and a half. It may sound like an ordinary bus ride, but in autumn, the route is an attraction in its own right. The bus climbs gradually through Naka-Karuizawa and Kita-Karuizawa, following the slopes of Mount Asama with red and gold broadleaf forests interspersed among the evergreens. Try to sit on the left side of the bus on the way up for mountain views. You cannot always choose your seat, but it is worth boarding early.

Kusatsu needs little introduction for onsen lovers. Its naturally gushing hot-spring water is among the most abundant in Japan, and it is so hot and acidic that locals developed the yumomi ritual—stirring the water with large wooden boards while singing and moving in rhythm—to cool it without diluting it. The center of town is Yubatake, or “hot-water field,” steaming in the middle of the streets. At night, it is illuminated in warm yellow light, and the steam mingles with the cool autumn air. Just standing there makes the journey worthwhile.

My favorite autumn spot in Kusatsu is Sainokawara, the rocky park west of town, where hot water flows in streams between boulders surrounded by red leaves. At the far end of the park is a huge rotenburo (open-air bath). Soaking in the hot water while looking up at the momiji canopy with mountain wind brushing your face is the kind of experience no photograph can fully convey.

Onioshidashi — a volcanic rock field beneath Mount Asama

Located directly along the Karuizawa–Kusatsu bus route, with its own stop, Onioshidashi is the remnant of Mount Asama’s 1783 eruption—one of the largest volcanic disasters in Japanese history. The lava from that eruption hardened into a vast field of jagged black rock. People long ago looked at the landscape and named it “Onioshidashi,” roughly meaning “where the demon pushed out the rocks.”

The autumn contrast here is spectacular: black rocks, red and golden shrubs growing between the cracks, and Mount Asama rising behind them, still regularly sending out plumes of smoke. In the middle of the park is a small Kannon shrine built to commemorate the victims of the eruption. From there, every direction opens onto rock and sky. The walking paths are well maintained, and a relaxed circuit takes about an hour.

My advice: do not treat Onioshidashi as a separate destination. Combine it with the Karuizawa → Kusatsu journey. Get off the bus, leave your luggage at the counter if possible (or travel light from the start), explore for 1–1,5 hours, and then take the next bus onward to Kusatsu. Buses are not particularly frequent during peak season, so take a photo of the timetable at the stop as soon as you get off.

Yokokawa–Usui Pass: a heritage route for railway fans and hikers

This is the most off-the-beaten-path of the four routes, but for me, it is also the most rewarding. In the past, the Shinetsu railway line over Usui Pass connected Yokokawa in Gunma with Karuizawa. It was notoriously steep and once required an Abt rack railway system to climb. When the Nagano Shinkansen opened in 1997, the railway section over the pass was closed, leaving behind an “open-air museum” that remains today.

The highlight is Megane-bashi, a four-arch red-brick bridge built during the Meiji era and spanning a valley. In autumn, red leaves frame its base beautifully. The old railway line has now become a walking trail known as Apt no Michi. You can walk through old brick tunnels, encountering a new photo spot every few hundred meters without crowds. At the foot of the pass, next to Yokokawa Station, the Usui Railway Heritage Park displays old locomotives. Children and train enthusiasts can easily lose track of time here.

And do not miss one of Japan’s most famous station specialties: Oginoya’s Toge no Kamameshi. This mixed rice dish is cooked in a traditional clay pot, a meal born in the days when train passengers had to wait at Yokokawa for an additional locomotive to be attached before climbing the pass. Eat the hot rice in the crisp autumn air, then take the pot home as a souvenir.

Getting there: JR buses run over the pass between Karuizawa and Yokokawa (there are not many services, so check the timetable in advance). Strong hikers can walk the old trail over Usui Pass from the Karuizawa side down to Yokokawa. It takes half a day and is wonderful during foliage season, but start early because mountain skies darken quickly. From Yokokawa, take a local JR train to Takasaki, then catch the Shinkansen to Tokyo. That makes this route a perfect final-day option on your way home.

Nagano and Zenkoji Temple — extending the journey west

If you have an extra day, or simply want to end the trip on a quiet, contemplative note, continue west by Shinkansen to Nagano—from Karuizawa, it takes only about half an hour. Zenkoji is one of Japan’s most important and oldest temples. It houses an image believed to be the first Buddhist statue brought to Japan and, notably, is not affiliated exclusively with any particular Buddhist school. Everyone is welcome.

The most memorable experience at Zenkoji is the o-kaidan meguri: descending into a pitch-black passage beneath the main hall and feeling your way along the wall in search of the “key to paradise,” attached directly below the place where the Buddha image is enshrined. It sounds simple, but spending several minutes in absolute darkness feels remarkably strange—as if your mind has been reset after several days of travel. If you stay overnight in Nagano, you can also wake early for the o-asaji morning service, when the head priest walks past rows of kneeling worshippers and touches a rosary to each person’s head.

Nakamise Street, the approach to the temple, is especially pleasant in autumn. Its shops sell oyaki (Nagano’s specialty baked buns filled with vegetables), soba, and ice cream. You can stroll and snack beneath rows of brilliant golden ginkgo trees.