reincarnation gone wrong?

(Note that the genders here are all extremely fluid; you could have a heterosexual or homosexual couple, or the roles could be reversed.)

A young woman remembers her past life, especially the man she loved. After saving up (or receiving) enough money, she plans to travel around the world in order to find the reincarnation of her lover. She finds a man that claims to be him, and they quickly fall in love and get married. However, the more time she spends around her new husband, the more she notices that he's not exactly as she remembers. She passes this off to both having led very different lives this time around. As time passes, though, the feeling that something isn't quite right about the whole situation grows larger and larger. Eventually, when she asks him, her husband admits to not being the man he claimed to be. What happens?

-I always liked (being a fantasy writer) the idea that the soul of her former lover split somehow upon reincarnation, and even though her husband may not entirely be the reincarnation of her former lover, he still has a piece of the split soul, and that's why they were attracted to each other and managed to marry before she noticed anything was wrong. From there, there's tons of possibilities. Do they get the rest of the soul back? What if all the pieces are in a bunch of different guys? What if she has pieces of her husband's soul inside her?

AAP by Tsukasa