With due ragards to you and with due empathy, I would seriously advise you to refrain from this as this kind of litigation shall be very lengthy and not much can be availed except prolonged bitterness. I am not discouraging you but circumstances are not very conducive for you. I strongly feel that by the time your case will be decided (may be a decade), the Apex Court will surely rule such relationship out of perview of S.375. Just consider,
1. There is no force involved in such matters..
2. It is like a void contract, we do this and we do that.
3. Both are party to this and this is always mutual.
3. It puts the girl involved in kind of naive category.
4. Misconception is defined in IPC, and in true since it is neither misconception, nor threat, nor deceipt. Misconception is untrue representation of fact, it has nothing to do with promise.
and the mute question is what if after years the girl says no to boy ??
Still get in touch with local layer, see if he can help you.