It is a movie so they didn't elaborate much every scene just give a glimpse of it.
Ends confuse a lot .he told her that he will be atree for her so don't lose hope and then they sat near water other lead come to suprise her then they both married so I thought happy ending but very last scene had shown he passed alone in the tunnel what we conclude that she is not with him ,she married to other lead so that can't be possible so she died but if she died then why he gave her hope. So confused.
About story ,it is very sad story, no happy moment . And ending is sad