I would like to be able to set a different notification in messages for each individual person I have received a message.
What device do you have?
I know on the S5 you can change the ring tone and make them individual by editing the contact card and you can change the messaging tone also by going under and editing the contact card and "add another field"
The Note 5 has that option also, but Message + doesn't seem to use that.
True, Messages+ does not allow for individual notification tones for each contact. If that's a deal breaker, then your only option would be to use a texting app that DOES allow this functionality.