The easiest snow destinations by Shinkansen (bullet train) are in Niigata and Nagano.
You'll see Niigata's Gala Yuzawa heavily advertised in Tokyo every winter. Just 80 minutes from Tokyo on the Joetsu Shinkansen, the resort even has its own station where you can step off the train, straight into the rental shop, and onto the gondola. However, not only Gala, but nearly all the resorts in Yuzawa and Minamiuonuma are accessible from Echigo-Yuzawa Station, the stop right before Gala Yuzawa—you just need to take a shuttle bus or switch to a local train. The closer resorts, such as Kagura, can be reached in about 20 minutes from the station, though you'll have to ride about 50 minutes to get to Naeba. Regardless, they make easy day trips, and JR offers an incredible variety of packages that include train tickets, lift tickets and even optional rentals for little more than the regular train price. While you'll need Japanese to navigate the website, you can also just head to a JR Tours desk at a major station and work with the staff to get set up.
Nagano is a little farther, but the train remains a fair option. For Nozawa Onsen, you can take the Hokuriku Shinkansen to Nagano Station (roughly 90 minutes), then change to the Shinano Tetsudo Kita-Shinano Line for 50 minutes. From Iiyama Station, catch the Nozawa Onsen Liner bus, which will get you to Nozawa Onsen in about 20 minutes. If you arrive after 8 p.m., you'll need to take a taxi, however.
If you're going to Shiga Kogen, you can get a local bus from Nagano Station to Shiga Kogen Prince Hotels/Yakebitaiyama Ski Area for ¥2,000 (85 min). You can also get a bus from the east exit of Nagano to Hakuba every hour from 8:20 a.m. to 10 p.m. for ¥1,800. However, be aware that the bus terminal is about a 10-minute hike from the main lift at Happo-One.
3. Chartered Bus from the Airport
If you're arriving in Narita or Haneda, generally you can just take the train to Tokyo or Shinjuku and start from there, and a Japan Rail Pass will often serve you well. However, a few resorts and services offer direct shuttles from the airport. For example, you can charter a direct bus from either airport to Myoko, Madarao, Hakuba, Nozawa Onsen or Shiga Kogen. It's pricey overall, but if you split it multiple ways, it starts to get pretty reasonable!
2. Bus Tour
This is a secret most people only discover after a few years in Japan: there are buses that leave Tokyo (usually Shinjuku and Ikebukuro) nearly every day heading to pretty much every major ski resort in the area! If the idea of an overnight trip in a metal tube makes you cringe, not to worry: there are plenty of spots within easy reach of Tokyo for a day trip.
While you'll need Japanese skill or translation software to navigate the sites, with lift ticket prices included in the fare—and rentals often an easy add-on—they are ridiculously cheap and fairly quick, though the price will vary drastically depending on the day, and a weekday is your best bet for ultimate value.
Major organizers include Orion, Road Plan, Sunshine Tour, Travel.jp and 1DayTour. 1DayTour in particular is both cheap and easy to navigate, with White World Oze Iwakura our pick for the best mountain in easy reach of Tokyo by bus.
Other common pick-up spots include Omiya and Kawagoe, and many of the companies offer tours from a number of major cities across Japan. Check the individual tour for details!
1. Foreigner-Friendly Ski Tour
There are a number of tour groups organized and run by foreigners in the Tokyo area that leave for snow country every weekend as long as the snow lasts. You'll be on a bus of pretty much exclusively English-speakers, and will spend your weekend sharing a room with members of the group—at random if you sign up on your own! While a little more expensive than a solo day trip, it's a great way to meet people and discover places to ski around Tokyo.
The two biggest groups are Tokyo Gaijins—which runs sports, outdoors events and parties throughout the year as well—and Tokyo SnowClub. The tours typically leave from Shinjuku Station.
So no more excuses! Get out there and get to the snow!