Urashima Taro was a fisherman. One day he caught a large turtle in his nets. The turtle was a symbol of old age and thus much respected. Urashima let the animal free.
To his amazment the turtle transformed into a lovely young woman. She explained that she was the daughter of Ryūjin the dragon god. She casts a spell on the fisherman enabling him to breath underwater then invites him to Ryūgū-jō.
Urashima was amazed by the vast underwater palace of coral and crystal but even more so by Ryūjin himself. The mighty dragon god’s coils were thousands of feet long and glittered with scales of every imaginable shade of green, aquamarine, turquoise, and blue. His head was crowned with branching antlers and his teeth were as long as scythes. Despite his daunting appearance the god had a kindly look in his eyes and took a liking to Urashima. He allowed him to marry his beautiful daughter and live in the splendid palace
For a while Urashima was happy but then he began to miss his land home and his parents. He was worried that they had no one to care for them in their advancing years. His bride accepted the situation and allowed him to return to the land so long as he promised to come back to her. The fisherman loved his bride and promised that he would indeed return.
Before he left she gave him a small laqured box tied up with cord and told him to never open it. If he did he would never see her again. Once again he gave his word. In her turtle form his wife escorted Urashima back to land.
Once ashore Urashima noticed that something was wrong. The surrounding mountains looked the same but the village was larger and looked very different. All the villagers were strangers. Looking around he saw no one he recognized. He hurried to his old home and found it to be nothing but a pile of rubble. Beside himself with worry he asked around about the people who had live in house and what had become of them. One very old man vaugly recalled a story of an elderly couple whose son had been a fisherman lost at sea. The story was supposed to have occurred 400 years ago!
It dawned on Urashima that time was not measures in the kingdom of the dragon god as it was on land. For every day he spent in Ryūgū-jō many mortal years had passed on land.
Perhapse hoping to find an answer to his awful situation he foolishly opened the box. A wisp if smoke rose up from inside it. This was time catching up with him. His hair grew white then fell out. His eyes dimmed, his bones grew frail. His skin wrinkled and sagged. His body dessicated as time sucked the life out of him. Later the villagers discovered the dried out husk of a man clutching a laquered box.
The date of Urishima’s fishing trip was around AD 478 and his return at around AD 825.