[quote=@Tomotaxi]
[@1Charak2]

Hmm, maybe a few actually. What sort of universe/timeline does this take place in, and year? Would it be more of the Apocrypha or Stay Night universe, or something original? Would the canon cast exist, and if not, could someone make an OC Emiya, Tohsaka, Kotomine, etc. due to them (potentially) not existing?
[/quote]

The Timeline it exists is independent of the other timelines, The year while not entirely focused I definitely envisioned it to be around the 2010's in period, Finally the canon cast does exist, but due to the fact we are in Tokyo, there is no real reason for any of them to appear. 

As such the only canons that would exist are on the servant side rather then on the master side of things.