Ichiya Kagiri no Cinderella

Kate is the personal secretary of Lucas, the crown prince of Ilha Beleza. And though he doesn't remember it, they actually met first when she was a child. That was when she fell in love with him. Of course, she hides her feelings from him—after all, he has a fiancée! Kate's dream of love can never be. But when his engagement is broken, he takes Kate with him on a private trip to his villa, where he plans to heal his heartbreak. On their trip, Lucas gets into an accident and hits his head hard. His memories get jumbled, and now he thinks Kate is his fiancée!

(Source: Harlequin/SB Creative Corp.)