Somebody call the Waaahmbulance!
wahmbulance
The best proof of concept you have is an extremely rough premise. Comparing it to the idea behind Hitman Reborn!, we can only see that they are remarkably similar. The fact that you flipped the ******** out instead of keeping your head cool shows that you probably lack the maturity to get this done.
When you pitch an idea, expect people to find an example of something that feels similar to your pitch. They will then question what makes yours special. Your job is to convince people that not only is your idea thought out but that you are worth working with to complete it.
You want a Japanese character but you
did not do the research to make him believable to anyone who isn't an idiot who squeals with glee at the idea of reading something about someone who is Japanese. You don't bother to spell correctly or use proper grammar. Worst of all, you act like a four-year-old whose parents refused to buy them candy at the supermarket and now you want the world to shut up.
Get the ******** over yourself. You are not a special little snowflake.