Jetstar are running their birthday sale.
You will only pay for a one way ticket getting the return air fare free, tickets start are $340.
You will never see a cheaper Japan flight unless your hiding in the under carriage (this is not recommended:)
so get on on it and you could be neck deep in pow next winter in Hakuba. Book your accomodation through our site and mention the sale and you'll get 10% bar cash back to spend on food and beverages in our hotel.