Let KAYAK do the searching
Based on KAYAK hotel searches, the most popular destination is Kusatsu (67% of total searches to Gunma Prefecture). The next most popular destinations are Minakami (16%) and Takasaki (9%). Searches for hotels in Nakanojo (8%) are also popular.
KAYAK users have found double rooms in Gunma Prefecture for as cheap as $19 (Kusatsu) in the last 3 days. The average price is $110.