How to Ride the Hero's Coattails

Ever read one of those webtoons where an obnoxious male protagonist transmigrates into his favorite game, uses his knowledge of the plot to become ridiculously overpowered, and somehow gathers a harem along the way? Now, imagine reincarnating into that story! That's what happens to Nahyeon, but unlike the freewheeling teenager of a hero, she has no interest in becoming the main character. After all, it's way easier to stick right at his side and benefit from his grand plan! Or so she thought...