Urashima TarÅ is a Japanese fairy tale about a fisherman who rescues a turtle and is rewarded with a visit to the RyÅ `` gÅ `` - jÅ , the Dragon Palace . Urashima TarÅ is a Japanese legend about a fisherman who rescues a turtle and is rewarded for this with a visit to RyÅ `` gÅ `` - jÅ , the palace of RyÅ `` jin , the Dragon God , under the sea .