There were some questions about who is the main character...
So I'll try to answer them here.
Now that this thread is here let's limit all the discussion about this issue to this thread: there were like hell a lot of discussions like that in other, sometimes complitely irrelevant, threads. It's kinda tiring to tell people the same things over and over again, so lets just say it once and then simply redirect those who are new to this place to this thread.
Now, lets start.
Before starting to debate, lets see who the hell is protagonist, so that we all will be talking about the same thing, not different ones. For that we can simply look in Wikipedia on page called "Protagonist". If you have complaints about the source please post them in this thread. But remember that they will be simply ignored if you do not suggest other, more reliable, source.
Originally Posted by Wikipedia
OK. Now we can start debating. The question is - who is protagonist, Tenma or Eri? Lets see how they both fit the difinition of protagonist.
Eri: For the last ~200 chapters, yes. Before that hardly appeared. Is in love with secondary protagonist (Harima), her feelings changed and progresseed through the story.
1) primary focus of a story
Tenma: Was postulated as focus by author, appeared often while story progressed. Didn't get much development though, was in relationship that has nothing to do with secondary protagonist (Harima). Her love in that relationship is static, was postulated in the beggining of the story, never progressed.
We can see that thier relationships are quite different - while Tenma's is constant which was never in doubt, Eri's grow from nothing to what it is now though hardships. The only serious hindrance for Tenma is Karasuma's leaving (and we do not even know if it really is an obstacle or not) that was overcome by the first time in the very beggining and now (~230 chapters later) seems to be rising again.
Tenma: No antagonists in her current relationship. May appear if she ever falls in love with secondary protagonist.
2) opposition from a figure or figures called antagonist(s)
Eri: Mikoto, Tae, Yakumo, Tenma.
Tenma as protagonist clearly doesn't answer our expectations here. At least for now (ch237).
Now lets go further in Wiki's article.
Eri: No, she doesn't simply express the qualities given in the discription. We saw her changing through the story together with hers' drawing style.
3) In some nineteenth century novels, for example, Wilkie Collins' "No Name," the protagonist, Magdalen Vanstone, is introduced with an extended description, and thereafter simply expresses the qualities given in the description. Similarly, in much "formula fiction" (as critic John Cawelti calls it), the protagonist will remain essentially unaltered for the duration of the story; no value judgement need be implied by an author's use of either type of protagonist.
Tenma: Simply expresses the qualities given in the description.
Lets now see: is SR an 19th century novel? Hardly. Could KJ use methods from 19th century when wrighting SR? Hardly, but possible. Now, what is "Formula fiction"?
While SR is the part of a genre that is the most typical for formula fiction, it itself is pretty original and totally unpredictibal, which makes attributing it to formula fiction extremely hard.
In popular culture, formula fiction is literature in which the storylines and plots have been reused to the extent that the narratives are predictable. It is similar to genre fiction, which identifies a number of specific settings that are frequently reused. The label of formula fiction is used in literary criticism as a mild pejorative to imply lack of originality.
Conclusio: SR is not formula fiction, therefor protagonist should be changing while story goes on and can't be static.
This is clearly our case.
4) A refinement can be introduced by an author using the first, evolving, type of protagonist as in Herman Melville's "Bartleby the Scrivener";
Tenma: No, her actions are not the center of novel. Though some of them (like kicking Harima of her house) are moving the story forward.
5) though a novel may center on the actions of another character, it is the dynamic character who typically allows the plot to progress in a manner that is conducive to the thesis of the work, and thereby focuses the attention of the audience.
Eri: Her actions are center of story and are moving it forward.
This part suggests that Eri can be seen as dynamic character, but only if her personal story is not the center of novel.
Eri: Does not comment on story.
6) It should be pointed out that the protagonist is not always the hero of the story. Many authors have chosen to unfold a story from the point of view of a character who, while not central to the action of the story, is in a position to comment upon it.
Seems to be our case.
7) However, it is most common for the story to be "about" the protagonist; even if the Main Character's actions are not heroic, they are nonetheless usually vital to the progress of the story.
We do not have narrator here. Akira and Itoko can be seen as the most close to this position characters.
8) Neither should the protagonist be confused with the narrator; they may be the same, but even a first-person narrator need not be the protagonist, as they may be recalling the event while not living through it as the audience is.
We have already reviewed this part. Note that in Eri's case there are 4 foils.
9) The main character is often faced with a "foil", a character known as the antagonist who most often represents obstacles that the protagonist must overcome. As with protagonists, there may be more than one antagonist in a story.
Noone died, left or was taken away from story yet.
10) Sometimes, a work will initially highlight a particular character, as though they were the protagonist, and then unexpectedly dispose of that character as a dramatic device. Such a character is called a false protagonist.
We clearly have 3 "main" subplots, that can't be easily separated from each other - Oudou, True Oudou, Flag. Others (like Apple) have nothing to do with main ones and could easily be removed from the story.
11) When the work contains subplots, these may have different Main Characters from the main plot. In some novels, the book's main character may be impossible to pick out, because the plots do not permit clear identification of one as the main plot, as in Alexander Solzhenitsyn's The First Circle, depicting a variety of characters imprisoned in and living about a gulag camp.
We can see both of then appearing rather often, we can see thier actions moving the story, we can see the fighting for thier love. BUT. Tenma's actions are moving another girls love story - Eri's, which suits for dynamic character but not for protagonist. Her own love story is with a guy different from secondary protagonist which would be rather strange for protagonist. And she hasn't made much progress in her feelings which are constant since the beginging. In contrast, Eri's actions are moving only her own love story, she loves secondary protagonist and her feelings changed from the begining of novel. So I do not see anything that prevents us from calling Eri protagonist.