The Fisher-Boy Urashima

Urashima Tarō is the protagonist of a Japanese fairy tale (otogi banashi), who in a typical modern version is a fisherman rewarded for rescuing a turtle, and carried on its back to the Dragon Palace (Ryūgū-jō) beneath the sea. There he is entertained by the princess Otohime as a reward. He spends what he believes to be several days with the princess, but when he returns to his home village, he discovers he has been gone for at least 100 years. When he opens the forbidden jeweled box (tamatebako), given to him by Otohime on his departure, he turns into an old man.