Mr. Idol's Bodyguard is a Mafia

A popular Idol named Ryu Zake needs a bodyguard who would protect him at all costs. Good thing Zake found the perfect bodyguard Ying Sheina a simple girl who works at a cafe restaurant. Zake didn't know that the girl who he chose has a big secret. That she is the heir of the whole mafia gang in Korea.

Ying Sheina leader of all Mafia has many secrets but one thing that you should know is that she is immortal.
She applied to be Zake's bodyguard because that's her mission to protect him at all cost BUT there's a catch. She can't fall in love with him no matter what happens. If she did she'll no longer be immortal and will die.

Sheina used to be Zake's lover in the past but that all changed because of a war. Sheina used to be the princess of Kagellion. While Zake used to be a her bodyguard.

The problem is that can she do it?