The route from Tokyo to Karuizawa is primarily served by the Nagano Shinkansen, specifically the Asama and Kagayaki trains. The Kagayaki Shinkansen is the express service, operating at speeds up to 260 km/h (161 mph) and completing the journey in approximately 1 hour and 15 minutes, with fewer stops. The Asama Shinkansen, while also efficient, takes around 1 hour and 30 minutes, as it makes more frequent stops at stations like Nagano and Ueda. Both trains offer various seating options, including Standard and Green Car class, catering to different traveler preferences. Onboard amenities include spacious seating conducive to relaxation, along with food and beverage service. The Kagayaki is the fastest option for those aiming for a rapid travel experience, while the Asama provides a slightly slower but more connected journey for those wishing to visit additional stations en route.