Check in and out were both incredibly easy. Our room was clean and well prepared.
We rented a "4 person Japanese style room" that three of us slept in. 3 people with large luggage and a backpack each was a comfortable fit - 4 people with large luggage may be a tight fit, but seems doable if you're good enough at packing things away efficiently (like the table in the room and your luggage). It would be especially doable if you have less luggage per person than we had.
Our visit was June 3. The Japanese style room did not, by my observation, have AC, but we opened the windows at night, and ended up with a pleasantly cool room by the morning. There was enough wind to cool the room off in the evening as well and keep it comfortable.
Breakfast was excellent, with a varied buffet-style selection. It included multiple beverages (tea, coffee, juice, water, milk), and a selection of both western-style and Japanese-style foods.
The staff were incredibly friendly and really wonderful. Front desk staff provided a page of clear English instructions for us at check in, which was really helpful. English signage appeared in the rooms as well.
I want to emphasize the friendliness and welcoming nature of the staff. We spoke little to no Japanese, but they made sure to make us feel welcome and accommodate us.
We did not make use of the baths, unfortunately, so no word on that amenity.
Cheap, clean room, free breakfast, and positive experience - I'd definitely recommend this place!!