That's a shame. Kids like more coloury round things like Pokemon and other stuf like that. It seems like the manga thing is stuck with kids nowadays. Maybe your style is too intrecate, too advanced or maybe it's for the publisher. Anyway thier loss and maybe you should stick to us grown kids that hang around here and worship your stuff.
You would have the freedom to do what you want. You could either do a cool shot of one of the characters or a cool shot of two them in some kind of cool fight pose. If you just do pencils, I can get someone to ink it and color it. But whatever you would like to do. Just love your work.