Another difference that I observed between the webtoon and drama is their world view in general. In the webtoon, it is possible for extras to voluntarily join stages (that they weren't assigned to) by being near the main/side characters. When they are physically near important characters, and a scene is triggered, they will enter that scene as extras. And if they are insignificant enough in the scene, they can also walk out of picture and go somewhere else to hang out while the main stage is still playing in the background. In the drama however, only Haru can go in and out of scenes freely. Everyone else can only move according to the script. But, I think there is a limit to navigating in the webtoon too, since in the scene where Danoh was being sent to the hospital, and during her time in the hospital, Haru was unable to go visit her (or even leave the school at all). I think this is because those scenes weren't meant to have extras in the first place. So the rule is, extras can only join scenes that need extras.