A high class hotel complex with three different buildings housing a variety of room as well as facilities such as a Gold's Gym, 2 onsen (one indoor, one outdoor on the roof), an indoor beach, a buffet with different cuisines from around the world, karaoke, bowling and a small arcade, Suginoi has pretty much all you could want to be able to never leave the hotel itself. It also has several large lights displays outside all year round, which are powered by local geothermal energy.
If you can't afford or can't manage to get a reservation to be able to stay here, the gym, onsen, beach, arcade, and bowling facilities are open to everyone, and their onsen in particular are well worth a visit. Suginoi is famous for its rooftop onsen and pool, from which you can get a wonderful view of the city and the bay. This outdoor onsen is mixed, but everyone wears swimsuits, so if you're not a fan of getting naked to bathe in onsen here, this may be the place for you! You can sit back and enjoy the view from the comfort of your own swimming costume while soaking in the sights of the illuminated fountains in the rooftop area. And if that's not for you, maybe take a trip to the indoor beach, Aquabeat (which is also a swimsuit-friendly area), with its tropical atmosphere, palm trees and waterslides!