Ichiya dake no Princess

In order to buy the highest quality yarn, fashion designer Jessica travels to the Principality of Alp’Azuri in Europe. While admiring the picture-perfect beautiful landscapes on a drive through the country, an out-of-control car smashes into Jessica’s car at full speed and knocks her out! When she regains consciousness, she finds herself at the royal palace. Alp’Azuri’s Prince Raoul’s fiancee died in that crash. Jessica blames herself for her death, but Raoul firmly asserts that it is not her fault…

(Source: Shojo Manhwa Scans)