Kusatsu Spa Resort Liner

hello! i'll be travelling to Kusatsu bus terminal from Tokyo on the 26th March 2013.

1) Will there be spa resort liner bus services during this period? I'm afraid that the roads the bus used are closed due to snow.

2) I will land in Tokyo only on the 25th March 2013. Is it necessary to make reservation for that bus? How would you advise me to do it?

Thank you for all your kind replies (:

Will there be spa resort liner bus services during this period?

Yes, it operates everyday of the year.

I'm afraid that the roads the bus used are closed due to snow.

No, the roads only get closed during exceptional snow storms which are rare, especially as late as late March when there may not be much snow left around Kusatsu.

I will land in Tokyo only on the 25th March 2013. Is it necessary to make reservation for that bus? How would you advise me to do it?

Although it falls into the spring school holidays, it is a regular weekday, so I don't think that the buses will be booked out. I think you should have little problems making the reservations after arriving in Japan at a JR ticket counter, e.g. at JR Narita Airport Station. In the unlikely case that the buses are booked out, you could always use trains instead:
http://www.japan-guide.com/e/e7403.html