Very similar...
Both have an angry\mother issue\daddy issue male leads
Both have an optimistic and out spoken female leads
Both have the over dramatic and obsessive girl who wants the male lead

I really enjoyed this series :D

The second series of Together With Me takes place AFTER Bad Romance The Series.. Has the same cast as Bad Romance The Series and Together With Me.

Together With Me is about Knock and Korn and how they got together BEFORE Bad Romance The Series.