I came with a family of 8 and I had the single room. The room is compact for a single person and comes with ensuite bathroom. When it says it's a single's room, it's a single's room, so 2 would be quite a crowd.
I like this hotel for the fact that it's close to restaurants and 200meters to the nearest tram. It is also close to the Goryokaku (10mins walk) where I had my first experience of the famous Japanese sakura season blossom. You can take the tram (7stops) to Hakodate Morning Market for seafood experience.
The hotel has a public bath that operates till late/ early hours of the morning on the top floor where you can have an 'onsen' experience though it can get crowded. Bath robe is provided in the room and you will have to take your towel for the bath. Try to regulate between less peak hours as 11pm can still have quite a fair bit of people surprisingly.
All in hour, it is a good experience and I like the hotel because of it's practicality, clost to restaurants and bars and minutes from the tram station. Highly recommended.