Not that long ago Narutaki and I were having a discussion about a phenomenon she likes to call side-character-itis. It is the tendency for fandom to latch on to certain side characters and completely obsesses over them to the point where they almost seem resentful whenever the main characters take the center stage. Hinagiku Katsura from Hayate the Combat Butler is a prime example of this. At times parts of the fans base seem genuinely surprised they are not watching a show called Hinagiku the Combat President. Shonen fighting shows tend to have this phenomenon as well as they often have generic protagonists to keep the story flexible. They offset the bland hero by making the side characters very vibrant. The problem is while fandom often gets obsessed with these more exciting side characters they are rarely strong enough to carry a show on their own. Often what makes them work as a side character is what keeps they from standing on their own as a main character.
I recently decided to re-watch some episodes of A Certain Magical Index during lunch at work and one of the poster girls for side-character-itis pops up immediately: Misaka Mikoto. Whenever a new episode of the show would come out it seemed the fan base interest was directly tied to the amount of the Railgun in any given episode. In fact she was such a popular character she was spun off into her own series. But interestingly enough she was strong enough to support her own show. So what separates the main characters in waiting from the merely flashy supporting cast? What separates the Fraisers from the Joeys? I won’t say that Misaka Mikoto has all the answers to that question. But she is a good place to start thinking about which characters can cut the mustard.
Firstly she has a dynamic power. The Railgun ability has the standard “I do a tremendous amount of damage” ability that is they keystone of the shonen hero. But like the Gum-Gum Fruit it has abilities beyond simply doing a tremendous amount of direct damage. She can use her power both psychically and mentally defensively. She can make a sword using magnetism or attack indirectly dozens of different ways. Anything that conducts electricity is an avenue of attack. She can brute force hack any machinery or network. She can even use it to fly in very select circumstances. Her ability set is a strong tool set that lets her work well when solo or with a team. In fact many people have argued her power is far more of a main character’s ability than Touma’s. And he is the main character of the original series.
Secondly she is strong personality on her own. While one of her signature traits is her unrequited love for Touma it is not her only shtick. If her life only revolved around Touma then she would be rather boring when he was not around. While most people know her as a gentle princess like character she is actually a loud and proud lioness when she gets down to the brass tacks. It makes her an easy character to like and sympathize with. It also makes her an interesting character to watch. She can often be in a high energy mode when you need fighting or to participate in some comedy but she can be thoughtful or vulnerable when you need drama. It also lets her play off the rest of the cast in different manners which you need for a centerpiece cast member.
She is also proactive. Too often the problem with side characters in it is hard to rope them into all but a select number of plots. That means you either have to move heaven and earth to get them to do anything or go back to the well of the few things that will motivate the character. Since Misaka has a strong sense of justice she will just as often insert herself into stories where people need help as often as she is dragged into situations by circumstance.
Despite all these factors there is always the outside matter of writing. A good writer can take an unlikely protagonist and weave compelling tales around them and a poor writer can ruin an otherwise rock solid main character. It is just that if the raw material is strong than it is more likely that the protagonist will have a good story evolve around them. Misaka Mikoto is not a moon who reflects the light of the sun but a brilliant star in her own right.