We stayed in a room with two single beds and a private onsen bath, from which we could see down to the beach. (There's a public bath, indoor and open-air on the top floor.) The loft-style room was amazingly beautiful and well thought out. We could not have been more comfortable. We opted for the half board plan, and were completely delighted at each meal, by the food, the service, and the surroundings -- since we stayed for 3 nights we were given a different private dining room on each night. Altogether an unforgettable experience.
The place is a bit removed from the hustle and bustle of the port side center of Hakodate - for that you'll need a tramcar (there's a convenient stop nearby with its own footbath onsen!) or an inexpensive taxi. From the hotel you can walk about 10 minutes to a very quiet and serene section of the beach.