Attention: For an updated version of the evolution chart, it is posted in this thread here.
Alright, this took forever to do, but I've finally managed to get a Kawaii Pet Megu Evolution Chart up! Evolving in Kawaii Pet Megu can be confusing, heck, it takes most people a week to even figure out how. The evolution chart starts out simple enough, but some Megu have a special evolution option, (those are the ones marked with a star) and that's where things start to get confusing. A "special" Megu will branch off away from the main evolution line, and will sometimes evolve back into a previous Megu form; this makes it more of a web rather than a straight-forward progression.
I used screen shots taken right out of the game - I just altered the background colors and some other things to my liking.