A short ver
Leo (black hair) and Ravi (white hair) is one person.
Leo symbolizes the lie and ravi symbolizes the truth.
the girl decided to up and leave and marry another guy giving LEO the wedding invitation.
Leo thinking it's best to let go of her tho he is actually a "beautiful LIAR"
(he is a liar at the end of the lyric instead of beautiful liar it became Cowardly liar ~ )
Ravi represent Leo's true feeling and does not want to let go of her.
Hence the scene where he (ravi) knock the key that the girl gave and wanting to go after her only to be hold back by leo. Also you see the struggle leo has trying to fight with himself through out the whole mv (fighting with ravi)
at the end he killed ravi strangle him (killing/ hiding his true emotion)
when he looked back the girl is also gone.
does that make sense ??? I'm I confusing you?
you can ask more questions if you are still confuses