Cinderella to Himitsu no Ichiya

Growing up, Kate has always had feelings for Garrett. He's always protected her ever since her bodyguard father died in the line of duty. But she can't stand that Garrett sees her as nothing more than a sister. One night, Kate is nursing Garrett's high fever when they suddenly fall into bed together! Thinking that her dream is finally coming true, Kate is stunned when she finds out that he is meant to marry someone else... (Source: Renta!)