Help Finding Manga?

I hate to do this, but I just really need to find this manga. I read it a few weeks ago and at the time it only had a few chapters released (maybe 3?). It's about this poor kid that lives with a group of orphans he's taking care of that suddenly switches places with the prince of the planet they live on. The prince and the main character look identical and everyone in the castle is fooled for a while until he admits who he actually is out of guilt and the wish to return to his family of orphans. Also he has this armband that transforms into a spear that should only work for the true heir of the planet, thus giving him the ability to save his planet from the many evil alien invaders.
I can remember a lot about the story, just not the name. If anyone could help me find it I'd be sincerely appreciative. Thanks in advance.

Bump. Serioulsy? Nobody recognizes this manga? If there are anymore details needed I can surely add more.

C'mon guys please? No one can give me some help here?

Over 100 people have viewed this post and no one can suggest something?

I might have found what you're looking for. Does "Sensei No Bulge" ring any bells?

Yes that's the manga I was looking for, but funny enough I found it myself last night when I was browsing around.

I NEED YOUR HELP!!!!

shounen, magic, adventure;

it was about a manga where this boy and girl, the boy was a doctor and he goes on a journey and this girl was with him and they use black magic to cure the people that has been infected by this disease, the disease makes them turn into monsters and the doctor cures him and then he moves on into the journey trying to kill all these disease that been going around everyone in the world , i think :/

well that what i think it was about i hope you guys will be able to find since i really want to find it PLEASE :)