One of the last few stories in the collection was about a man who took a nap under a tree in his garden and dreamed that the king of the Japanese equivalent of Fairyland summoned him to his kingdom. He dreamed that he married the king's daughter, brought order and prosperity to the province he was given to administer, and had seven children. He spent twenty-three years in this dream kingdom, and then his wife died and he was sent home to the human world after her burial. When he woke, he discovered that he was still in his garden, and the friends who had been sitting beside him the entire time reported that he had slept for only a few minutes.
The story itself, minus the obvious indicators of cultural context, could as easily be an Irish tale of the Faerie Folk or a Native American tale of the Little People (or regional variant thereon). The existance of such supernatural kingdoms, and their occasional borrowing of unwary mortals for good or ill (often in sleep, and often near certain natural features such as large trees or hills) is a common theme in folklore in most cultures and would probably be familiar territory for readers of nearly any cultural origin.
Those two friends who had watched the man sleep also reported that they had seen a butterly fluttering near him, which then landed near the tree and was pulled underground by a large ant; just before the man awoke, his friends claimed to have seen the butterfly fly back out of the hole in the ground and return to him.
In both Japanese and Chinese folklore, butterflies are commonly the embodiment of a human soul, which may be living, near-death, or dead. The man and his friends speculated that the butterfly may have been the sleeping man's soul, and the ant could have been the representative of the "fairy king" who had come to fetch him. There was a large ant hill at the base of the tree, into which the butterfly had been pulled, and the men decided to excavate it.
When they dug into the ant hill, they found stick-and-grass constructions which resembled tiny buildings in the layouts of the towns and cities the man remembered from his time in the mysterious kingdom. In what had been the throne room of the royal palace, he saw a male ant larger than the others surrounded by a court of smaller ants. Recognizing the layout and the landscape, he found the hill on which his dead wife had been buried, and on it he found what looked like a tiny Buddhist tomb; inside he found a dead female ant.
There the story ends.
Leaving aside the fact that the whole story is contrary to everything we now know about ant behavior and physiology, it's an interesting tale of a man pulled into a fairy kingdom in a dream, only to awaken and discover that very kingdom inside an anthill in his own garden.
It becomes a very different and rather unsettling tale when you realize that at the story's end, his excavation destroyed his own kingdom from above.