Since I don't know the specific 'girl in blue story', it's difficult to say who the main character is. But as the title suggests, it's likely the girl in blue.
If the 'blue girl story' is a fable, the main character would be this girl who might be named something related to blue, like Bluebell or Azure. She could be facing challenges like dealing with mean characters in her village or trying to find a lost blue gem. However, without more details, this is just speculation.
Obviously, the main character is the girl. Since the title mentions 'the girl with the blue mustang', she is likely at the center of whatever events the story tells.
The main character is the girl in 'the girl with the blue lantern story'. The blue lantern is probably an important element related to her. She could be a young girl with a curious nature. Maybe she is an orphan and the lantern was left to her by someone special. And all the actions and events in the story might be seen from her perspective as she goes about her life with this special blue lantern.
Obviously, the main character is the girl with the blue ribbon.
Presumably, the main character is the ghost girl. Since the title focuses on her and it's her story set in the Blue Ridge Mountains.
Since we don't have much information about the 'the blue man story', it's difficult to say who the main character exactly is. But, given the title, it's likely that the blue man is the main character.
Since I don't know the exact 'blue king story', I assume the main character is the blue king himself.
I'm not sure specifically as I haven't read the story, but it may be about a girl's journey with her blue lantern.
One main element is the Blue Corn Girl herself. She is central to the story. Another is the corn, especially blue corn which holds great significance in Hopi culture. There might also be elements related to the Hopi's spiritual beliefs, such as the connection between the girl and the divine. And perhaps elements related to the natural world like the land and water which are essential for the growth of corn.
The main idea could be about a little girl named Blue. Maybe it's about her daily life, her dreams, or some special experiences she has. Without more context, it's hard to be more specific.