I think I figured it out it's the setting...
The original is in school setting while the spin off is in the mafia setting... because of this your more inclined to view more adult than normal even if they are the same age canonically and the normal setting is demon related and in hell
Second note, pretty much everyone is aged up. If not, they were already adults. The only exceptions are Ameri and iruma.
Iruma was aged down, Ameri is ambiguous. Childhood friends means she could be 14 to about 22. I think 17-19 makes most sense though, which is still aged up.
