Aria Sera is a saint candidate gifted with exceptional divine power. One day, she is summoned out of the blue only to find Crown Prince Siegfried waiting for her. “Would you become my fiancée?” “Absolutely not.” What he does not know is that he is Aria Sera’s ultimate oshi the very man she uses as material for the “thin holy books” she secretly writes, her own self‑published fantasy romances. Told that this engagement is a political move to save the kingdom from crisis, she reluctantly agrees. But for some reason, Siegfried’s courtship never stops, no matter how often she insists: We agreed this wasn’t actually going to end in marriage… right!?