From House of Hozz
First we should probably do some short non-continuity strips. Like these ones!
Characters need to start off less mature and developed than we eventually want them to be. Hugh, how long has he been fighting evil, not forever! Hugh is only recently started fighting evil. Plotline where they decide to find out what he's up to.
Wacky hijinks, a few plotlines involving Hugh. Zombies, get kicked out because of it. Hunt for a house, stay at their parents, their father directs them to the house. Summer break. Dad says "you can't all stay here, go to our cabin, it's been in the family forever... etc, it's our first house, we never sold it, we keep meaning to fix it up."
Cabin should be some place close enough that they can actually live there, but removed from the city in it's "own little world" kind of location (like the White's house).
Same as one, up to...
Got kicked out of our apartment. They don't want to tell their dad why. they say "we had an incident" and avoid the topic. Dad figures out that their powers are starting to develop. He sends them to the cabin, hoping that they will end up in TwinWorld and discover where they are from and who they are.
Instead, start the story with Oswald in the library. He could go over a short description of where and what is going on, then go back to "the beginning" and start with the silly stuff from idea one or two. This gives us a context in which to say to the audience, "This will be a serious story, but not quite yet."