Some say it's possible, some say it's not. My opinion is by large on the basis of the mentality of an individual and very much guided by the emotional involvement in the relationship. Again a guiding factor would be a one-way love or a reciprocated love. I guess you got the flow of my thought here. So, let me try and be clinical here (in the treatment of this topic).
1. 
One-way Love: In this case, what one ends up with is the guy/gal feels very strongly for the other one. Deliberates over the matter, and ends up bugging a few friends. Such is the flow of events as would have been often observed by some here, that at one point of time, the individual decides to proclaim the love that they have for the other one and finally come to conclusion. Result: "Yes"/"No". In case of a "No", one would find some sulking away to some remote corner of their immediate civilization and finally come back and join the crowd to be what they have always been. To remain friends, their relationship need to have the foundation of friendship and not love.
One-way Love: In this case, what one ends up with is the guy/gal feels very strongly for the other one. Deliberates over the matter, and ends up bugging a few friends. Such is the flow of events as would have been often observed by some here, that at one point of time, the individual decides to proclaim the love that they have for the other one and finally come to conclusion. Result: "Yes"/"No". In case of a "No", one would find some sulking away to some remote corner of their immediate civilization and finally come back and join the crowd to be what they have always been. To remain friends, their relationship need to have the foundation of friendship and not love.2. The Reciprocated Love: In this case, after things peter out, it is always difficult to be friends... or at least stay in constant touch. The reason being that the level of attachment was so much that they had never imagined life in any other shade. Some who take a pragmatic approach to life and are mentally prepared for something, might be able to salvage a meaningful relationship still. They call it being friends... somehow for me it is the remains of the love that was!!
Now the moot point is really possible to remain friends?? My answer is yes... it is possible.. but it's success is conditional!! It all depends on whether you are mature enough to deal with this new scene in your life? What was the basis of your relationship? Wonder how I can be so sure?? Been there done that... and not so long ago.. say less than a year..... :)
The decision is always yours.... the choice can be a difficult one.... but then it has to be done!!
P.S. - a hurried post.. so the thought process might appear very broken!!
