From KENAZ:
Among his father's works as a cartoonist, Kang Chul's favorite character, Yeon-ju, had a birthday party one day when she was spending her ordinary life.
However, while falling asleep for a while, she opened her eyes in a strange place, and in front of her stood Kang Chul, the character that she had only seen in the cartoon.
When I woke up, this place was too much like the world in cartoons, not reality.

Original Webtoon