Get Mount Fuji Onsen Day Background. Both offer stunning views of mount fuji (on a good day). Onyado fuji ginkei is a hotel located by the lake.
My advice is to stay in a hotel without an onsen (it's cheaper) and pay the admission the same day.
Onsen by mount fuji covers onsen 101 and how we loved our stay at lake kawaguchiko; Fuji and the lake can be seen from the outdoor onsen and all guest rooms. I love the ocean air, the view of kamakura and mt fuji, and the shrines and small shops around the island. Fuji 5th station and lake kawaguchi, with additional stops at the freshwater springs of oshino hakkai and the oshino ninja village.