We had a great stay at Toya Sun Palace. The resort provided a bus service that picked us up from Sapporo for free, saving some money, though unfortunately it took over an hour longer than scheduled. The resort is impressive with the glass-walled lobby overlooking the lake, though the onsen areas were a bit smaller than expected. The Japanese style room was basic but comfortable, and housekeeping makes up the tatami sleeping mats at night. The room has its own small bathroom and a view of the lake, though the view is better elsewhere on the resort. Breakfast and dinner were included. The buffet had a very good range of food in our opinion, for both dinner and breakfast, and the quality was good by typical buffet standards. The separate male and female onsens had a range of baths, including an outdoor one overlooking the lake. It could be very crowded in peak season. The water is 38-40 degrees, which feels very hot but you adjust to it. There is a very faint smell of chlorine (much less than a normal swimming pool), but no sulphur or other smells. There is a nightly fireworks show on the lake which was nice, Tahitian entertainment performances everyday, and wearing the yukata around the resort was also enjoyable. We made the mistake of only staying one night, which was too short and didn't leave time to see the water fun park or go to Nakajima Island on the lake. We would definitely consider staying at Toya Sun Palace again, though maybe not during crowded peak season.