Choejong Boss-ui Aeinirani Ohaeimnida

When protagonist Jun Karentia enters a game as a support mage, she's all set to guide hero Fabian to success. But, oops! The game throws her a curveball when Fabian ditches her in round two, and Mayer Knox, Fabian's rival and secret final boss, recruits her as vice-captain for his corps. The problem? He's the final boss and now everyone thinks they're dating! Now, Jun's mission is to outwit Fabian, transform the final boss into the game's new hero, and put an end to those pesky romance rumors.
(Source: Tapas)