The Star Festival takes place today in all of Japan (except Sendai, we celebrate next month.)
Here is the history of the Tanabata Festival as recounted in my favourite Japanese Lessons online:
The Star Festival finds its roots in a Chinese legend (Kikkoden) about the love between the weaver and the herdsman (represented by the stars Vega and Altair). As a result of their great love for each other the weaver neglected her work on clothes for the gods, and the herdsman neglected his cattle. As a punishment the emperor of the heavens moved the stars to opposite sides of the Milky Way and stated that they should only be allowed to meet once a year on the seventh day of the seventh month. On this night a flock of heavenly magpies use their wings to form a bridge that the weaver can cross to join her lover. The magpies will only make the bridge if the seventh is a clear night; if it rains the lovers must wait another year.
During the festival poems are written in honor of the two separated lovers, and women pray to the weaver that they might acquire skill in weaving, music, poetry, and other arts.
The Tanabata song goes like this:
笹の葉 さらさら (Sasa no ha sara sara)
軒端に ゆれる (Nokiba ni yureru)
お星さま きらきら (Ohoshi-sama kira kira)
金 銀 砂子 (Kin gin sunago)
The bamboo leaves rustle, rustle,
shaking away in the eaves.
The stars go twinkle, twinkle;
Gold and silver grains of sand.
If you'd like to write a wish click away. I hope it is granted!