How to Get a Wife
Various things play into this, and it is still being worked on and improved. What we know right now is your social status matters. Having a huge bank account helps. But doing quests for them every chance you get improves your relationship with them quickly. Once they are at a higher fondness level, you can give them gifts, mainly chocolate. After they love you, you can marry them.
You can view your current relationship status by holding down RMB.