There's no way to know exactly who the main characters are without reading the 'running on air fanfiction'. It could be original characters created by the fanfiction writer, or it could be characters from an existing franchise that the fanfiction is based on.
As we don't have any information about the content of 'running on air fanfiction' other than its title, it's impossible to determine the main characters. They could be anyone from superhero - like figures with the power to run on air to ordinary people who discover this extraordinary ability in the course of the story.
I'm not entirely sure specifically as it could be a very unique or less - known fanfiction. It might be about a story where characters seem to be defying gravity or having a very light - footed, almost ethereal existence, like 'running on air'.
Well, in addition to Aang and Katara, there might be other characters that play important roles. For example, Sokka, Katara's brother, could show up and offer his strategic thinking to help Aang and Katara in their adventures. Also, Toph, the earthbending master, might make an appearance. Her earthbending skills and her no - nonsense attitude could add an interesting dynamic to the story. However, at the core, it's still Aang and Katara who are likely to drive the main plot forward in this fanfiction.
Without having read the 'masters of the air novel', it's hard to say exactly who the main characters are. However, given the title, they might be ace pilots. There could also be ground crew members or instructors who play important roles in the development of these 'masters of the air'. Maybe there are some characters who are not directly involved in flying but support the 'masters' in other ways, like family members who provide emotional support or military commanders who assign them missions.
There's no way to know for sure without more information. It could be pilots, aircrew, or even people on the ground related to air operations.
I'm not sure specifically without having read it, but it could be a young, ambitious person trying to make their mark in the world.
I'm not sure specifically as we don't have much information about the story. But it could be a young couple who are just starting to fall in love.
Since I don't have the details of 'love in the air novel', it's difficult to name the exact main characters. But generally speaking, in this kind of romantic novel, the main characters are the ones whose love story drives the plot. They are likely to be individuals with unique personalities and backstories. Maybe one is a bit of a dreamer while the other is more practical, and their differences and similarities will be explored as their relationship unfolds.
I'm not aware of the particular 'castle in the air novel' you mentioned. But likely, the main characters would be individuals who are either trying to build their 'castle in the air' or are caught up in the allure of someone else's. It could be a group of adventurers who set out on a quest based on a far - fetched prophecy, believing they can achieve the impossible. Or it could be a lonely figure who has an elaborate vision of a different life and is struggling to make it a reality.
If it's the 'Air' anime, the main character is Yukito Kunisaki. He is a traveling performer who is on a quest.
Since I haven't read 'A Mouthful of Air Novel', it's hard to name the exact main characters. However, often in novels, the main characters are the ones with the most complex storylines. They could be a protagonist who is on a journey of some sort, maybe a personal or emotional journey. There might also be supporting characters that interact with the main character and help to develop the story further, like a friend, a family member or an antagonist who creates conflict.