
Tanabata (Festival of the Star Vega ), is a Japanese event originating from Chinese QIXI Festival.
July 7 is the date to celebrate the meeting of Orihime (Vega) and Hikoboshi (Altair), two lovers who were separated by the Milky Way. They are allowed to see with each other only once a year on the seventh day of the seventh lunar month.

I guess it could explained as a Asian Valentine's Day.

Every year on that day, a lot of festivals and events are held in Kyoto.

・Jishu Shrine
The most famous festival - TANABATA Festival is held at Jishu Shrine (inside of the Kiyomizu Temple).
Jishu Shrine has a long history, and there is a famous power spot for love. On the date of July 7, many couples visit there to make a prayer by writing their name on a piece of paper, then tie it to the bamboo tree, wishing for the enternal love.
☆Date: 7 July
☆Time: 14:00~
Fee: Free (but need to pay for the enter fee of Kiyomizu temple) ☆Trasportation: Kyoto city bus #80 to gojozaka from YUMEYAKATA
・Kibune Shrine
During TANABATA festival, there will be light illumination of lantern.
☆WEB: http://inkyoto-kanko.com/1953.html
☆Date:July 1 ~Aug 15
☆Time:10時~
☆Transportation:KyotoCity Bus #17 to DEMACHIYAMAGIEKI station and change to eizan train to KIBUNEGUCHIEKI station then get on CityBus #33 to KIBUNE Stop. Also at MATSUNOO-TAISHA will have TANABATA festival too.