This song is really nice ! (:
Hmmmm, if you all don't know the storyline , it goes like this (:
Her boyfriend cheated on her , and she realised it , & of course they broke up . Than she's sad & kept crying. and the boyfriend still loves her , so does she . So the boyfriend feel very guilty for making her so sad, and well , committed suicide. That explains the Gun sound. So ya , it's a sad song.

Oh , and this song is the theme song for this Taiwan Drama called , 下一站,幸福 , which is practically super nice ! (: I love that show , but it's still showing in Taiwan , so ya , now watch until Ep 4 only . :X So ya , Hope you like this song as much as i do ! (: Enjoy! :D