Annika-Rudra: Rudy loves Annika and adores her as his didi. They are very funny. Full of Life. Very Perceptive. They are the life of the party.
Om-Soumya: Om and Soumya has a calming effect in a Chaos. They both speak from their heart. Very matured. Both Om's and Soumya advice on Relationships&Love. Also Om calls her his Sister.
Now Coming to
Shivay- Om's Mystery girl: Based on this , I think Om's girl will be much like Shivay and Shivay will be best friends with her. Some one with Grey Shades but still a strong ,lovable character.