Why R U?

Jung Lee Won, a university student majoring in acting, has a rivalry with Kim Ji Oh, a directing major. Despite their constant bickering, they often have to work together. Unbeknownst to Jung, his younger sister is writing a web novel where he and Kim Ji Oh are lovers. When he discovers her secret, he vows that if he secretly likes Kim Ji Oh, the novel’s storyline should come true. As they spend more time together, Jung begins to question if his feelings for his enemy are becoming something more.

Synopsis: MyDramaList