Obake — Jamie K. Schmidt

Ashley Connors' life is heating up again when a demon steals her boyfriend Kai's soul and eats it. It's up to disgraced samurai Terasaka, and Sada the lust demon, to help her get Kai's soul back. But the cost of restoring Kai is that Terasaka sacrifices himself, not only being banished from walking the Earth, but also from Ashley's life.