The venue of the meeting is Jyozankei View hotel (定山渓ビューホテル) at Joyzankei in Hokkaido, Japan. The hotel is large enough to accommodate everyone. There are different types of rooms (western-style and Japanese-style) that you can choose from, so we recommend you to stay in this hotel.

The room charge at a conference rate (link) is between 15,000 and 20,000 (JPY) per room. Single occupancy is possible but will be charged at the full rate. With two persons or more, it will be between 8,000 and 12,000 JPY/person (depends on the number of occupancies). The room charge includes “breakfast” and “dinner”, except for the day of excursion.

The booking of the room should be made through the WISE local organizing committee (Method will be announced soon).

To share a room, please coordinate on your own. If you need assistance, please let us know:

   Takuji Waseda (The University of Tokyo)
waseda_admin+wise2019 [at] edu.k.u-tokyo.ac.jp

There are other accommodations nearby the conference venue.  Some may allow one person to occupy the room, but customarily they recommend multi-person occupancy.  For your reference:

Booking.com (booking site)