Let KAYAK do the searching
Based on KAYAK hotel searches, the most popular destination is Fujikawaguchiko (75% of total searches to Yamanashi Prefecture). The next most popular destinations are Fujiyoshida (19%) and Yamanakako (4%). Searches for hotels in Kōfu (2%) are also popular.
KAYAK users have found double rooms in Yamanashi Prefecture for as cheap as £39 (Kōfu) in the last 3 days. The average price is £146.