Once upon a time, there was a fisherman somewhere. The fisherman went past the sea one day and he saw numbers of beautiful tennyos bathing. There was some hagoromos hanging on a tree near by. The fisherman has never seen such a beautiful thing before. The fisherman knew that it belongs to the tennyos so he quietly took one home. The tennyos  cannot go back to the heaven without the hagoromo. So she went to  the fisherman and ask for her hagoromo back.
The fisherman pretended that he knows nothing about the missing hagoromo. So The tennyo can only married him. They live happily together, and gave birth to several babies. A few years later, the tennyo know the location of the hagoromo that the  fisherman hide,  from the song her children was singing. The tennyo finally got back her hagoromo and returned to
the heaven. Leaving her husband and children behind.

*Sorry if any information is wrong*