what the japanese did on this day??!!

Basically, the Japanese celebrates this day by writing wishes either in the form of poetry or in tanzaku form . I guessed you may ask me what is a tanzaku?In fact tanzaku is like a matter that made up by small pieces of paper which the japanes mostly hang them on the bamboo or sometimes even combined with all sorts of decorations. Many citizens in Japan will have their own traditional costums on Tanabata which mostly related to the Obon traditions. There is even one traditional song for Tanabata,which is as shown below:

Sasa no ha sara-sara (笹の葉　さらさら)
Nokiba ni yureru (軒端にゆれる)
Ohoshi-sama kira-kira (お星様　キラキラ)
Kingin sunago (金銀砂子)

Translation:

The bamboo leaves rustle,
shaking away in the eaves.
The stars twinkle;
Gold and silver grains of sand.

Source: http://en.wikipedia.org/wiki/Tanabata_Festival 

Source of picture: http://shibuya246.com/wp-content/uploads/2009/07/shibuya-matsuri.JPG