True enough. I didn't really look at those that closely in the one eyeful I used for this
As it's pretty much established this is a sequel to it, I see a fandisc being unlikely
The cover uses a side character from the original title. I thought it was the sensei, but with closer inspection the two designs do differentiate.
It can be a true sequel, either a continuation of one of the routes like with IroSekai, or a new MC with new heroine(s) and story, although this one is rather unlikely in my opinion.
Then it also could be an alternate scenario with this new girl.
Only time will tell what the accurate procedure is.
Until then, these are my speculations on it