I realise I might've written myself into a corner in regards to creating a harem by choosing to start at the moment I did.
So far I've come up with two possible solutions:
1) Retcon a couple of events that have happened.
2) Re-write this, starting at a previous point in the series. (I'll post the redone version under a new title and discontinue this one)
You can vote on these two ideas or suggest alternatives, I'll be waiting for your feedback.