Attire at ski resort

I come from a tropical country and first time going to ski resort in Nagano in Dec. I have a few questions:
a. The winter coat/sweater/scarf/gloves that we are going to wear around Japan ok at ski resort or do we have to change to parkas etc?
b. Do we have to wear waterproof clothing?
c. Can these be rented at resort so we carry less luggage into Japan?
Any advice is appreciated. Thanks.

first time going to ski resort in Nagano in Dec. I have a few questions:
a. The winter coat/sweater/scarf/gloves that we are going to wear around Japan ok at ski resort or do we have to change to parkas etc?
YES if you want to ski, no if you only walk around in the streets in the resort (you can of course wear sweaters, scarfs and thick gloves with a parka).. Mind you if your winter coats are rather formal they would look kind of strange in a ski resort..
b. Do we have to wear waterproof clothing? YES if you ski..
c. Can these be rented at resort so we carry less luggage into Japan?
I have never heard of it. it might be possible but would be expensive. why not wear ski type parkas everywhere rather than city type dressy winter coats? I wear parkas in a big town well away from ski resorts in winter!
however you need special ski pants, boots etc. (you may rent ski boots with skis etc.
.

regarding question c. Rental ski wear is available at virtually every ski resort in Japan. Costs range from around 2000 to 4000 yen for an adult for one day. Children's prices are roughly half the adult price.