My Perfect Boyfriend Was Actually a Tyrannical Emperor?

In a romance novel where a war-obsessed tyrant falls in love with a sun-like saintly heroine, Carolina is reincarnated as an extra with absolutely no connection to the original plot. For Lina, an ordinary working girl who cares more about whether she has to work late tomorrow than about the romance of the century, her mundane daily life is turned upside down when, one day, a boyfriend with dazzling good looks appears as if by fate...

...I had no idea back then.

“...Lina. Are you planning to eat the emperor and run?”

That the cutest, most lovable boyfriend in the world was actually the Emperor!

A secret romance born of a misunderstanding, Lina’s heartbreaking efforts to protect her boyfriend from the cruel Emperor (?)! A sweet yet dangerous romance inside the imperial palace between a clueless girl and a straight-talking Emperor!

(Source: KakaoPage, translated)