In it was your old age ..." As always with folklore, there are many different versions of this story.
Also, there is a version in which he dies in the process of aging (his body turns into dust), as no one can live 300 years. It was the favorite Japanese folktale of Lafcadio Hearn.
A shrine on the western coast of the Tango Peninsula in northern Kyoto Prefecture, named Urashima Jinja, contains an old document describing a man, Urashimako, who left his land in 478 A. Manga and anime adaptations include Clannad, Detective Conan, Evangelion, Yu Yu Hakusho, Urusei Yatsura, Love Hina (whose lead male character is called Urashima Keitaro, and with a girl named Otohime Mutsumi), Gintama, Kamen Rider Den-O (the namesake of the Imagin Urataros, given by Naomi), Cowboy Bebop, the same year that Oz author Ruth Plumly Thompson adapted it as "Urushima and the Princess of the Sea" for The Philadelphia Public Ledger.
The name Urashima Tarō first appears in the 15th century (the Muromachi period), in a genre of illustrated popular fiction known as otogizōshi; the story itself is much older, dating to the 8th century (the Nara period).
Older sources such as Nihon Shoki and Tango no Kuni Fudoki (丹後国風土記) refer to Urashima Tarō as Urashimako.
is the protagonist of a Japanese legend about a fisherman who rescues a turtle and is rewarded for this with a visit to Ryūgū-jō, the palace of Ryūjin, the Dragon God Nadraka, under the sea.