Talk:The Letter She Kept Waiting For/@comment-121.6.4.226-20140728012512/@comment-6192846-20140728014359

Well for the guy in this song:

"The song was originally intended to be a continuation of Story of Evil, but was later scrapped by mothy as a dead plot point."

It is not part of mothy's official continuity, per his words (check the trivia). So don't even worry about him.

The difference between Allen and Alexiel is a name. Irregular is arguably the same person too, though we're not sure about the specifics at this moment.

Hänsel however is a completely different character.

I recommend reading their individual articles that I've linked above to get a grasp of who these characters are. It's understandable that you're confused so feel free to read on anything and everything confusing you (we also have events articles like Reign of Evil if you want to start on the broader setting).

My recommendation is to understand that many of these character share the same likeness (and Vocaloid) but are entirely different characters. There are usually in-universe explanations for this however. Accept that and it's easier to understand who these characters are.