The man who stepped out of the summoning circle seemed somewhere between a young man and a middle-aged man. He had the consistently refined and elegant bearing of an English gentleman. Deep blue butterflies fluttered around him:
Oh my, I'm only a mere mortal, young man. I'm just a little, just a tiny bit mischievous!
Don't be so serious. I'm a good person, you know! I'm James Moriarty. So, are you the one asking for my help?
A Heroic Spirit summoned for some inexplicable reason, despite there being no Holy Grail War, decided it probably wasn't a problem if he temporarily forgot his real name. This world, full of superheroes and everyday threats like alien invasions and the imminent destruction of the world, was rather interesting.
That is, until he saw a curly-haired detective at 221B in England and heard someone call him by the even more familiar name "Sherlock Holmes."
The Professor is a Heroic Spirit from FGO. He leans toward the elegant English gentleman version from the original work.
Also, a certain detective Ruler who doesn't wish to reveal his name is on his way.