I'm going to use A.D as short for American Dragon: Jake Long.

So i understand it might be a little weird to ask for manga suggestions base on a T.V show however I haven't read a manga like A.D, and i thought this might be better because i'll be able to be more specific. Everything I mention is in the premise here https://en.wikipedia.org/wiki/American_Dragon:_Jake_Long.

What i'm looking for:
-Happy ending,

• Completed and fully scanned (or very close completed and scanned)
• Both characters has some sort of secret identity (if only one prefer the girl). In A.D he's a dragon and she is a dragon hunter.
• Characters has some sort of relationship with both the "real" person and the secret identity. In A.D she is the sidekick to his main rival and they fight often, also his "true self" has a romantic relationship his her "true self".
  -Doesn't need to have a clear cut good and evil but if it does the girl is evil and the guy is good.
  -Doesn't need fighting.

Two manga kinda like this are:
-Tonari no Kashiwagi-san except

Her secret identity doesn't last long, he also doesn't have a significant relationship with her secret identity and finally it doesn't make a huge impact on the relationship when she tells him.

-Superior/Superior Cross except

haven't read this yet was going to but someone told me the ending really bad and kinda destroys the story. (If this isn't the case feels free to recommend it