Travelling from Kyoto to Sapporo

I'm trying to get from Kyoto to Niseko and want to ride a sleeper train. How do I book this? In particular, I am interested in booking the Hokutosei train from Ueno Station to Oshamambe.

You can make bookings at any JR station in Japan, starting one month ahead of travel date.

There is also a direct night train from Kyoto to Hokkaido, called "Twilight Express":
http://www.japan-guide.com/e/e2356.html

Hi there,

Thanks for your quick response. I won't actually be in Japan until a few days before I catch that sleeper train. I'm flying in from Melbourne, Australia, around Christmas day, and planning to do this big overnight journey on New Year's day. Because it's peak travel period, I'd like to get this ticket booked early to ensure I can travel on that particular day. Is there anyway I could get a train ticket booked online perhaps?

Is there anyway I could get a train ticket booked online perhaps?

I am afraid, I don't think there is such an option. On what day will you be traveling?

I'll be travelling from Melbourne to Tokyo on the 27th of December, then travelling to Kyoto on the 30th and leaving to Sapporo on the train on the 1st of January. Should I perhaps risk it and buy my ticket from Tokyo when I arrive?

The 1st itself is not such a busy day in terms of traffic volume, and the night trains to Hokkaido might not book out, but I am not sure. You can check vacancies here:
http://www.jr.cyberstation.ne.jp/vacancy/Vacancy.html

Note also that, while the Hokutosei run daily, the Twilight Express opearates only on selected dates.