two main purposes
What is the osananajimi? What narrative purpose does she serve? Why, so often, does she seem to be included only to lose? Is there a difference between the "losers" and the "winners", or is it entirely due to authorial whim? These are the questions I attempt to address here. Note that this is a work in progress, and that little work beyond developing the basic methodology has been done. Additionally, in order to focus on one specific archetype/role (and prevent scope creep!), I intend to address only female childhood friends who are not the protagonist in non-shoujo/josei anime/manga.
Let us examine the role of the osananajimi in the romantic comedy/drama. Often, she is the first to be in love with the protagonist, yet she rarely emerges victorious; why is this? What purpose is served by her love, and her loss?
My contention is that she represents a "childish", non-sexual love; her violent reprisals towards (inferred) lewd behavior suggest to me a symbolic representation of the discomfort felt by young people as "adult" romantic feelings begin to appear—she is the childish mindset, recoiling in fear of change, while the main romantic lead, usually beautiful, represents an "adult" relationship. Consider the case of the beautiful, mysterious, transfer student, who suddenly appears and disrupts the daily routine; her coming heralds the end of childhood, and the common breaking of the "childhood mariage promise" shows the move away from naiive, childish, loves into a sexual/romantic mode. Thus, in a narrative based around maturation or coming of age, the childhood friend, in this role, cannot win—she is defeated by the inexorable march of time. Her love belongs to the past, and to the childhood being left behind as the cast enters young adulthood.
But not every childhood friend loses. In particular, in science-fiction narratives, she often wins. Consider Kaminagi Ryoko of Zegapain, or Senomiya Akiho of Robotics;Notes—both emerge victorious, despite the appearance of "mysterious transfer students" in their lives, and contest for the affections of their childhood love (the protagonist). If they do not discredit the claims above, they must serve a different narrative role, but what is it? To answer this question, we must first look at the surrounding events that define these stories.
In these narratives, the protagonist's assumptions about the world around them are questioned, and shattered; in Zegapain, the entire world they exist within is shown to be false, and in Robotics;Notes the peaceful everyday life assumed to be "truth" falls apart, revealing a network of conspiracies and global threats. Both stories focus on a different fear of maturation; they are talking about the fear of responsibility, of the increased complexity and gravity of adult life. The boring, peaceful, secure, lifestyle shown in the early episodes is an illusion—much as the relative shelter and security of childhood falls away as one becomes more independent, and more responsible for their own wellbeing (and the wellbeing of those who rely on them). The same theme—the changes of early adulthood—are explored here, but the challenge that the narrative focuses on is different. But what of the childhood friend? What is her place in this schema?
Simply, the osananajimi here represents constancy. She is a point of reference—though many things may change, other things (personal identity, perhaps?) remain. Though the easy comfort of childhood may fall away, and though the protagonists find themselves in a radically different role, in a radically different world, the childhood friend shows that the previous life was not a lie, and that the protagonist's basic person remains the same, albeit with a newly matured outlook. The romantic requital mirrors the reconciliation of the protagonist's persona with the revised understanding—the movement from childhood to (young) adulthood, and the acceptance of a new, more complex, world.
Overall, then, if these interpretations are correct, we should expect to see childhood friends predominantly "losing" in school life/coming-of-age stories, and predominantly "winning" in more serious examples of science fiction stories (those that are not harem genre; this tends to behave according to the prior rule) . I also, though more hesitantly, expect to see more tsuntsun traits in the former, juvenile, role, and fewer (or less strongly exhibited) in the latter.
This concludes my preliminary analysis. In future work, I hope to examine a selection of characters specifically from shounen and seinen anime, and to use the previously explicated method to analyze them and determine the validity of the claims above.