Seems like they made changes from webtoon and Class 1 last scene. Uniform is different than after transfering on Class 1, maybe the scene where the bully from the class tried to pick on him is gone as well, which was the 1st chapter of the webtoon. The fight on the teaser is vs Wolf from webtoon, which is a kinda advanced chapter, so I wouldn't be surprised if they made their own new version of the story. Class 1 was just a ~10 chapters flashback from the webtoon which they completely changed and made a great drama out of it, so wouldn't mind if they can deliver same quality.
Uniform is different than after transfering on Class 1, maybe the scene where the bully from the class tried to pick on him is gone as well, which was the 1st chapter of the webtoon.
The fight on the teaser is vs Wolf from webtoon, which is a kinda advanced chapter, so I wouldn't be surprised if they made their own new version of the story.
Class 1 was just a ~10 chapters flashback from the webtoon which they completely changed and made a great drama out of it, so wouldn't mind if they can deliver same quality.