When love is so beautiful, why do they hate it?

Dushmani: A Violent Love Story

In order to settle personal scores; two gang leaders, Jai Singh and Oberoi fight for many years in gang-wars. There enmity multiplies when Jai's younger brother, Suraj falls in love with Oberoi's sister, Sapna which forces Suraj and Sapna to elope. Jai then locates the duo and brings them back to try and convince Oberoi to get them marry albeit successful.