Phoo Chai Hua Jai Mai Pie Rua 1995 on netflix

Rud is in love with Valai but is afraid to tell her. He has bought an old ancient ring intending to give it to Valai as a birthday gift but he never gets the opportunity to give it to her, so he wears it on his finger but is unable to take it off. The next morning, a miracle happens to him when he wakes up and finds himself turned into a pretty woman, but when the night falls he turned back to himself again.