The Romance of the Sun and Moon

Kim Jongdae was just an average office worker, going home from a stressful day in the office. He was checking the updates of the webtoon he's reading when he was hit by a car. He felt the immense pain his body received before he fell on the ground. The next thing he knew when woke up was that he was already inside of the webtoon he was reading… Not as the main character but as the side character's elder brother.