it's the feeling

fly to the sky's sea of love
http://www.youtube.com/watch?v=Yv3hQsAJEzo

fly to the sky's forever
http://www.youtube.com/watch?v=ufUv6EOR21M

v6's feel your breeze
http://www.youtube.com/watch?v=mJKzdqxYQPo

southern all stars' sea of love (can't get the pv)
http://www.youtube.com/watch?v=JOxYb1EXac8

all 4 songs have something in common.