but if your imagination good enough it can be awesome fanfic, i remembered when i'm still active reading fanfics at Fanfiction.net and some author bring in some reference to a certain game and even a character from another anime
the easiest way to get them into one story line (based on my author experience, and i'm one of those author who like to bring chara from another world)
for example on digimon (since when i'm still active 90% fanfic that i wrote on my book is digimon's)
-On digimon there was exist a time dimension bomb, there you can do likes the chara to get messed with it and ended on other dimension
-When belphemon rage it caused every time he attacking the space is distorted there you can do likes someone from other dimension accidentally got messed with that space time distortion
and something like that, or if you want to create your main chara got helped by lolis from another world you can do things like
-Visiting their world and convince them to get you by making a situation where they are in trouble (you can use this as an extra chapter before returning to main line, maybe they call it filler if i'm not wrong)
since when i'm writing this post i'm starring at broken's signature which is Tina then let's make her as an example
you can make a situation where she is in big trouble (if it me i'll make a situation where RENTAROU IS DEAD
) and snatch her
or you can make your chara be a hero for her by somehow defeat her master oh if you're good at battle related fanfiction (which you need to describe every of their move in order to make the reader understand what kind of battle they are in), your chara can be the one who defeat her instead of rentarou
sorry if my answer not match your question and sound devilish but till now i'm still doing chuunibyou like that though now only within my head
EDIT :
or if you fell guilty for doing things above, i had one thing to say PARALLEL WORLD IS EXIST
you can have your very own lolis for yourself while the "original" one not touched with that you can had the lolis you desired while the original not touched
or you can create your lolis chara yourself, but unfortunately for me i'm unable to do so since even to think what my main chara looks like is trouble me a lot
