get a sturdy plastic one with a brush, lol.
This one that's on top of amazon right now is fine.
and don't forget - scrape ALL the ice off your windows, and brush all the snow off the top of your car.
you'll (ideally) get ticketed in the north if a cop sees you with snow and ice sliding off from the top of your car. It's a hazard to those behind you.
Depending on where you will be living and working, my advice is don't.
You're only here for a few months and already plan to keep driving to a minimum. Boston is particularly difficult - the confusing signage, the windy narrow roads, low visibility of road paint, the pedestrians and cyclists that don't pay attention, the endless potholes, the snow, the ice, the salt, the complete lack of parking. And if you are street parking, you need to be careful for snow emergencies, street sweeping, etc. Towing companies are bandits & liars - and the City does almost nothing to regulate them.
I shit you not, my off-street, but non-garage parking space is $250/month. There's parts of town where $350+ is normal.
Better to leave your car and use trains.
Most of us use public transit everyday - even buses. I realize that in most of the country, public transit has a stigma. There is no stigma here - dishwashers and bankers stand side-by-side here on their way to work. It's cheaper, safer, often faster and less hassle.
Anyways - if you must use a car - get yourself some good All-Season tires. Winter tires are great, but at least with All Seasons you can continue to use them when you move home in May. Our roads get cleared pretty quickly (it's a populated area, afterall) - so you will not need chains.
Get yourself a Ice-Scraper/Brush Combo thing. Something like this.
Your car will need a few minutes to 'warm up' after you start it. If it's an old car, you may notice your breaks will tighten. Just give it a minute to warm up before you drive and it'll be fine.
If there is a large parking space anywhere close by you can drive around in - I would recommend taking your car there on a snowy/icy day and practice sliding around and get a feel for things.
Air! Low temperatures and low pressure cause your tires to deflate. Keep an eye on your tire pressure, after you drive up here, you'll probably need to fill it. Fill it again after a particularly cold night.
Keeping some kitty-litter in your car might be a good idea. If everything turns to ice, kitty litter is a good way to create traction and get yourself out of a tight spot.
plastic ones from amazon are cheap and may not last forever - but that's fine for Dallas, since we rarely get that weather.
https://www.amazon.com/AstroAI-Detachable-Scraper-Ergonomic-Removal/dp/B07V37GVY9/
I use one of these:
https://www.amazon.com/dp/B07V37GVY9/ref=cm_sw_r_cp_api_i_CAZZ1FZ4S5N708AMJA1D
I can tell you what I like and why. But I do not know what is available in Japan.
AstroAI 27 Inch Snow Brush and Detachable Ice Scraper with Ergonomic Foam Grip for Cars, Trucks, SUVs (Heavy Duty ABS, PVC Brush) https://smile.amazon.com/dp/B07V37GVY9/ref=cm_sw_r_cp_api_glt_fabc_SQCFK9E73XATGVN01VD2
MTB Lightweight Snow Shovel Snow Pusher, Pack of 2 Sets, Blue, 52-in Long with Aluminum Handle and 22 inch x 10 inch Poly Blade https://smile.amazon.com/dp/B07SM6G1SD/ref=cm_sw_r_cp_api_glt_fabc_X0H7EBMSD1S1NR1NQJ0Q
But again, I am not sure what you can find in Japan.
Never driven in a Montana winter, but I'm from Minnesota so I can answer some questions about winter driving in general. But first, what kind of car are you going to be taking?
Generally, interstate highways and other major routes (especially in cities) will be just fine to drive through as long as there hasn't been a snowstorm in the last few days. Crews usually do a good job keeping the roads salted and plowed. Even if there has, the roads are still drive-able, but just be a bit more careful. If you do end up driving through snow, please turn your lights on! It is very hard to see cars on the road when there is snow whipping everywhere. If there's enough on the ground to obscure the lines, just follow the tracks of the car in front of you. Don't worry about your speed, do whatever makes you feel comfortable. As some others have said, keep a bag of sand/litter in your car in case you get stuck, to use as traction. The scraper/brush is a must have! Something like this should be fine. If you park your car outside, you~~'re probably going to~~ WILL wake up to a frosted over car, hence the scraper. Make sure that your defroster works properly, otherwise you are going to get a lot of fogged up windows. They can also do the job of scraping the frost for you if you have 15-20 mins to let your car run before you take off. A collapsible shovel like this is good to have just in case you get snowed in. A set of emergency warm clothes is a good idea as well.
I've never gotten snow tires on the family cars but we do have 4 wheel drive. Get a scraper to remove snow from your windshields, trunk, hood and roof (like https://www.amazon.com/dp/B07V37GVY9/ref=cm_sw_r_tw_dp_x_q-QvFbTMTMMPE). Remember that snow can cover a sheet of ice so drive slowly! Tap your brakes periodically to make sure you can still stop and just drive slowly overall. People might beep but just wave them past you.