Due to my past bad experience with these “moun boli” sisters i don’t believe in this thing anymore. The only relations are those which are blood relation and there is nothing like moun boli behan, bhai, maan or baap .. 
Dude, u literally have no idea what “a sister” mean .. .. u have it thats why you said. Yeah, I have my elder bro - he is the best .. but
- I can never have that fun which a bro-sis have .. fighting with each other and still loving each crazily
- I can never have someone about who i can act as ultimate guardian .. ..
- I can never cry on someone’s wedding (sounds bizarre .. but it seems cute to me)
- I can share all the latest gizmo/gadget stuff with bro .. but i can’t share the girlfriend thingy
.. u know .. - Study also has proved that Girls are way better listeners than Boys .. so having a brother would not efffect than having a sister
Oh man - there are countless things i can write on and on .. .. I used to tell me friends that i miss “A sisters love” in my personality and they used to say .. “you are being over sensitive” (which is kind a true .. I am at this topic) .. .. but now this study clearly tells .. .. ..