I'd heard many variations of this story during my travels in the east. A herdsman and a divine weaver fell in love. The weaver's father was displeased by her love for a mortal. He turned the river that seperated Heaven - the realm of the gods, and Earth - the realm of the mortals, into the Milky Way. Seperated, the two mourned for each other. Seeing the love between them, the weaver's father allows the two to cross the Milky Way once a year, on the 7th day of the 7th month. They dwell together for a short summer night, only to part again for another year.
I came across an old shepherd in Japan one evening. He told me the story, as we sat at his campfire. When he finished his tale, he pointed at the sky and said, "There is Tanabata, the Weaver, waiting to cross the Milky Way. I followed his arm & saw the bright star Vega in the constellation Lyra. I tried to determine if he was referring to the star or the constellation, but I could not understand his answer.