No, none of these characters are or have ever been real people. Some aspects of them are taken from real historical figures, but only a few things here and there. I'm assuming that this isn't a troll message
Assuming this isn't a joke message, I think the anon miiiiight be asking if the characters exist independent of VOCALOID (like, if they were from an unrelated series that the VOCALOID is a parody of or something)?
To answer that, no. Mothy made the original songs using VOCALOID, and many of the novel characters have their character designs based on VOCALOID characters. It's part of why the copyright situation is so complicated.