2 things and it would be a masterpiece!

Masterpiece, I don't know about success or lots of money...

1- More serious... I like little girls kicking ass as anyone, but if it had a more serious tone and some of the first episodes had no kabaneri (giving more of a hopeless vibe) then it would be better

2-A few more episodes, sometimes looks like they didn't have planned what to do and did rushed things...