The Undertaking of Hart and Mercy - Megan Bannen
This is more than just a romantic fantasy. For a while, as you are reading it, it is everything. Oddly, utterly believable and full of characters you wish existed, it will put you out of any reading slump. Each time I walk passed it on my shelf, I give the spine a little stroke.
From the back:
Hart is a marshal, tasked with patrolling the magical wilds of Tanria. It's an unforgiving job, and he's got nothing but time to ponder his loneliness.
Mercy never has a moment to herself. She's been single-handedly keeping Birdsall & Son Undertakers afloat in defiance of sullen jerks like Hart-ache Hart, the man with a knack for showing up right when her patience is thinnest.
After yet another run-in with Merciless Mercy, Hart finds himself penning a letter addressed simply to "A Friend". Much to his surprise, he receives an anonymous reply, and a tentative friendship is born. Little does Hart know he's baring his soul to the person who infuriates him most. . .