The manga is about these 2 brothers who are pretty affectionate to each other. They get these tattoos at the beginning to symbolize how they're part of this organization and then end up being sent to this other world and get separated. The brother who looks like a girl gets a ring which houses a genie who used to know his past self and at one point he gets rescued in the dessert by a prince/not prince. Everyone seems to think that he's a girl and he has some sort of healing power.

I really want to re-read it if anyone knows the title.