Yumemi no Majo to Kokkou no Shinigami

The princess of a magical land, Liliana, gets married to the Emperor Bernhard, who is feared as the "Grim Reaper of Black Steel." In spite of the worry people around her feel, Liliana is overjoyed and says, "Please love me forever." When she writes a very long love letter, people suspect it's a cipher, but it looks like they met in a dream before...?

At the same time, the equilibrium with the two neighboring countries is about to collapse. What will happen to this newlywed couple who are at odds with each other?

(Source: Ichijinsha, translated)