Why didn't Dee have a physical body in the outside world?
So why didn't Dee have a physical body in the outside world while Alice did? It's weird 'cause you know...Alice was the one who died 14 years ago? Didn't really feel the feels in episode 12 'cause I was bothered by this.
Dee appeared as a ghost because her physical body was still stuck in class 3-4, while Alis had a physical body outside because he was already buried by a proper gravekeeper. Therefore his body wasn't in class 3-4 like Dee, and could appear normally since he was part of the world outside.
Dee has a physical body later on because the world class 3-4 created had been destroyed. Her physical body was released.