Crystal Kay collaborates with 'Girlfriend' BoA May 21st,2009 Crystal Kay (23) is celebrating the 10th anniversary of her debut this year. Her first song for the year will be a collaboration with BoA (22), titled "Girlfriend feat. BoA." It will be used as an image song for the Japanese release of the American romantic comedy "He's Just Not That into You." About seven years ago, the two singers became very good friends after having the same dance instructor. As a result, the two said they really enjoyed recording the song, which talks about friendship between women. The movie, which features an ensemble cast including Ben Affleck and Jennifer Aniston, opens in Japanese theaters on August 1. TokyoGraph 45 sec. Teaser (Audio Only) http://www.youtube.com/watch?v=mT6-LHnGHCE