Retired black knight Lina and her husband Joshua have relocated to the idyllic eastern region—for Lina to recuperate from her old injuries, and Joshua to work and study in hope of becoming the next prime minister. With renewed passion for one another, the two are happy to get the chance to live in peace together...but their tranquility doesn’t last long! A ghastly illness with connections to Lina’s past has broken out in the neighboring region. Desperate to find a cure for the sick and to prevent the disease from spreading further in the poverty-stricken territory, Lina and Joshua travel to the small village of Riberry to get to the bottom of the mystery. However, the puzzles don’t end there. Why have a literally washed-up black knight and a half-drowned girl appeared in Riberry? And just who is this woman who keeps calling on Joshua and sending him letters? Doesn’t she know he’s married?!

Heroic black knight Lina can fell monsters and slay dragons with ease, but when it comes to romance, she’s still a total rookie! After dozens of dates ending in failure, she’s ready to give up on her quest of finding a husband, even if the idea of a family is an alluring one. The hitch? Marriage is a requirement for all black knights! You see, the ability to use old magic—essential for safely slaying dragons—is a rare gift, so there’s staggering pressure for black knights to pass their power on to the next generation. Worse yet, Lina’s in immediate danger without a partner to bless her armor. But it’s going to take the right person... Enter the prime minister’s aide, Joshua Granwell, a handsome and talented white mage who’s a perfect match for her mana. He’d make the ideal spouse for Lina—except she does not want to marry a noble. A contractual marriage might save Lina’s life, but surviving the marriage hereafter will be a challenge all its own!