There is an archetype in anime and manga that I’ve begun calling the “Emergency Heteronormative Character.”
In the beginning, many manga creators do not know where their comics will end up. Rose of Versailles was supposed to focus a lot more on Marie Antoinette than Oscar. Kinnikuman famously began as a superhero parody before it turned into a full-on wrestling manga—and all because its authors, Yudetamago, really got into the latter. A single storyline in Yu-Gi-Oh! about a trading card game permanently altered its entire trajectory. I think the same thing happens with series where character relationships are important.
Some love triangles know exactly who the end girl will be, whereas others might not arrive at an answer immediately (or ever). But I have also seen series where a particular character, usually a minor one, seems to exist just in case, as if above them is a message that reads “Break Glass if Heternormative Romance is Necessary.”
I have never read Slam Dunk, but I’ve heard about Akagi Haruko: the female love interest of the protagonist, Sakuragi Hanamichi. She is a fairly important character at the start (being the one to spark Hanamichi’s entry into basketball), and she’s even the focus of the anime’s extremely beloved first ending sequence. But over time, she recedes into the distance because the dynamics between the players themselves are what really draw people in.
The appeal of shounen sports series for shippers plays right into this pattern. Whether it’s Prince of Tennis or Yowamushi Pedal, there often seems to be a girl character who is like an anchor on the port of heteronormativity, allowing a manga creator to double back if need be. Even Saki has some of this energy in the earliest volumes. The character of Koutarou began as the sole male member of the mahjong club, acting as a potential male audience stand-in to witness the girls in their nonchalantly risque glory.
BL and yuri potential often drive a good deal of the relationship interest in series like the ones mentioned. However, the Emergency Heteronormative Character can even exist in series that are pretty heterosexual too. In Rokudo’s Bad Girls, you have Tsuyukusa Mizue, the only non-delinquent girl in the series. She’s meek and cute, and always worried about how the main character Rokudo seems to be turning to the dark side. And while the anime is on an accelerated timeline, the early part of the manga makes it pretty clear that she could have been Rokudo’s “saving grace” if the series had gone a little differently.
Emergency Heteronormative Characters aren’t automatically bland, and they can be fun and charming in their own right. That said, they often feel like the product of an author hedging their bets, and they typically shine less brightly because they are simply not meant to be in the spotlight as much. I also have to wonder if these characters exist on some level for in case a title needs a quick romantic conclusion should things need to wrap up quickly. However, as we further leave the era where nice and neat heterosexual relationships are seen as necessary, maybe the archetype will have to evolve into something else entirely.
OGIUE MANIAX 