Responses
I think the artstyle is very similar if not the same as it used to be. They just grew up! That's why their faces look so much different. It's 10 year difference after all :3
Them maturing has nothing to do with the obvious change in art-style. Go back and look through from volume 7 to recent chapters.
The art did change, Ichikawa Kei re released the first volumes with the new art style a while ago
Oh my, i miss these guys so da*n much! Art changed, they sort of look rounder. I like the old artstyle because it felt more nostalgic for me. But still, this is one of the greatest reads I ever had!