CHARACTER BLOAT VS. CAST DIVERSITY
Love Hina, the anime version in particular, has a lot of characters. However, these characters fall into three basic tiers:
Top Tier: Keitaro and Naru. These are the twin suns that the rest of the story orbits around. Will they get together? Will they get into Tokyo U together? Who is the promise girl? The prologue, Keitaro's blurred memory of the childhood promise to get into Tokyo U with the memory girl, makes these three questions one and the same. When the story begins, Keitaro's failed to get into Tokyo U three times -- but in its own way that was him keeping his promise. After all, Naru wasn't old enough to even try once until then! The story of Love Hina then is the story of these two trying to answer this three-part question, and going through every possible permutation. First, Naru is the promise girl, then Mutsume is, then neither of them are, then Naru is again. First, neither of them get in, then Naru does but Keitaro doesn't (in effect, since his broken leg prevents him from attending even though he's accepted), then again it looks like neither will go (when Naru wants to go with Keitaro and Seta in search of the Turtle Civilization), but finally they both get in and go. And as for being together, or not, they go back and forth on that issue so many times that you need a scorecard to keep track.
Second Tier -- Reflections: Seta, Shinobu, Motoko, Mutsume. These are characters who are either central to the Keitaro/Naru story, or are reflections of it. Seta is the person Keitaro will become (which is why it's significant that Naru had a crush on him), whereas Shinobu is the person that Naru was, for instance. Motoko is the anti-Keitaro ... super-serious, a macho girl instead of a less-than-masculine guy, and so forth -- but like Keitaro, the basic lesson she needs to learn is to stand up and face her problems instead of running away from them. Mutsume is ... well, it's hard to say what Mutsume is! She's a mirror image of Keitaro (klutzy, absentminded, etc.), and an inverse of Naru (gentle, very forward with her feelings, persues Keitaro instead of punching him into orbit), but somehow manages to be the bridge between them both several times.
Third Tier -- Echoes and Extras: Su (both Kaolla and Amala), Kitsune, Sara, Hitani & Shirai, Grandma Hina (who is more of a plot device than a character), Mei, Haruka, Tama, Kentaro, Kanako, Nyamo. These are all characters who serve some kind of utility function in the story, but aren't really what it's about. In this category, several of these characters are disposable, in my opinion. Neither Mei nor Sara added anything at any point, for instance. Kentaro made an interesting rival for Keitaro when he first appeared, only to get turned down flat by Naru right off the bat and spend the rest of the series making jokes about getting "another cameo." Hitani & Shirai are intentionally disposable -- to the point that even Keitaro forgets who they are when they aren't around and needs them to remind him every time they appear.
Note that the third tier characters aren't necessarily insignificant -- Kaolla and Kanako in particular are major forces in the overall story at one point or another -- but they're either enablers or obstacles for Keitaro and Naru. Neither one has an interesting story of their own. (This is slightly less true of Kaolla in the anime, since she has the whole Peter Pan thing going on, but that is something of an add-on rather than a piece of the main plot.)
RUNNING GAGS, THEMES, MOTIFS
Tokyo University and the Hinata Hotsprings -- Places of Power
Getting into Tokyo U is the macguffin that keeps things going. The real-world Tokyo University is famous for being very hard to get into; in Love Hina, this difficulty takes on mythic proportions. Whenever a place or thing is very hard to find or reach, it ends up referencing Tokyo U somehow. The lost-sought ruins of the lost turtle civilization on Pararakelese Island are at an oasis with a rock formation that looks like Tokyo University. In Molmol, the ancient capital of the lost turtle civilization is named Todai -- another name for Tokyo U -- and again, the temple looks like Tokyo U. Tokyo U isn't just a school that Naru, Keitaro, and Mutsume want to be admitted to, it's a symbol for everything that people strive for and is hard to reach.
It's also a symbol for true love, which is arguably the hardest thing in the world to find. "If two people who love each other get into Tokyo U together, they'll live happily ever after!" is the premise that the rest of the story is built on; again, because Tokyo U is more of a symbol than a real place, it has this power.
Hinata Hot Springs, and the Hinata Apartments in particular, is another magical place. In the anime series, Haruka talks about how in Hinata, dreams and reality mix and become blurred. This is shown explicitly several times, such as when Motoko falls asleep at the temple and ends up sharing the video game dream with Keitaro and Naru, or when Naru becomes a pop star and Keitaro is unsure if their conversations about promising to pass the next year's exams are real or dreams. In the epilogue of the manga, Shinobu says the Hinata Apartments have the power to make anybody's dreams come true -- with the proviso that they can't give up trying.
Keep Trying / Keitaro's Indestructability
If "Keep trying and don't give up!" is the theme of Love Hina, then Keitaro's seeming immortality is a manifestation of it. It doesn't matter how many times Keitaro is knocked into orbit, eaten by gigantic mechaturtles, drowned, or run over by Seta's van, he always pops back up in the next panel or by the next scene -- to the point where other characters begin commenting on it -- and commenting on its absence when he actually does get a broken leg.
In the anime, when Motoko is learning the "evil splitting blade" by using Keitaro as her practice dummy (with emphasis on the dummy), Seta explicitly comments that it's Keitaro's love for Naru that makes him so strong. His willingness to come back for more even when he takes a pounding is what saves Naru, inspires Motoko, and in the end makes the happy ending of Love Hina happen.
Tama, four incarnations of Mecha-Tama (including one that goes on a kaiju-esque rampage), Gidget, the Parakelese flying turtles, the lost turtle civilization ... Love Hina has definitely got something going on with turtles. (The Nintendo version of Kietaro in Motoko's dream starts out as a turtle, as well, and given Keitaro's importance, when something happens to him it's worth taking a look at.)
I haven't figured this particular motif out yet, if indeed there's special significance to it at all. There may be Japanese cultural significance to turtles I'm not aware of ... or it could just be that Ken Akamatsu watched a lot of Gamera as a kid, who knows?
Amnesia / Who Are You Again? *crash*
The slippery nature of memory, and childhood memories in particular, comes up again and again. Keitaro's memory girl from his childhood is an amalgamation of Naru and Mutsume; Naru doesn't remember Keitaro from her childhood at all on a conscious level until much later, etc. And of course, one of the many running gags of the series is that when a character hasn't been around for a while, the first thing anyone says to them when they return is, "Um ... do I know you?" (Poor Hitani & Shirai almost never have an appearance where somebody remembers them.)
But even when memories are lost on a conscious level, they're still there, driving the characters. The manga story where Mutsume hits her head and regresses to childhood is the most explicit declaration of this. Naru and Keitaro have to play along with her to bring her back into the present, and the three of them re-enact the whole sandbox scenario, as much as anything else, to refresh Keitaro and Naru's memories and explain how things ended up the way they are. (Mutsume's double sacrifice, not only of stepping aside for Naru but taking on Naru's sickly nature so that Naru can be strong, makes this a particularly poignant episode. Until this point, the depth of Mutsume's affection for the primary couple is implied, but never clearly stated.)
Running Away / Being Chased
At some point, just about every regular character in Love Hina is running away from something. Keitaro runs away every time he thinks he's failed, and Naru has to chase him down and bring him back. Naru runs away every time she gets close to actual intimacy with anyone. Motoko is running away from the burden of running her family's school. Shinobu has run away from her family troubles. Kaolla is running away from being forced to marry her brother. Haruka is running away from (or at least avoiding dealing with) her past relationship with Seta. Seta is running away from whatever cult is chasing him in this issue. ;) Kitsune is running away from ... well, something. Responsibility, maybe?
The irony of all these chases is that usually, the thing the person is running from is actually something very good for them, that they're irrationally afraid of. (Prime example: Keitaro running away from Seta, who's trying to return the exam ticket Keitaro dropped.) It's only when the person stops running (or, more commonly, can't escape) and turns to face their fear that they discover that what's been chasing them wasn't so bad after all.
This is a silly little pun that took me a few passes to catch. I'm pretty certain it's deliberate, but it's very subtle.
Three Holes / The Three Eyes of Molmol?
In the subtitled version of the anime only, there's a bit of throwaway business that almost every time a scene begins with two characters in conversation, it includes a reference to some object with three holes in it, e.g., "It had three holes in it, and it looked cool, so I really wanted one!" or "Good-bye! I'll look into those three holes you mentioned." What does it mean? Does it mean anything?
One thing that comes to mind is the religious symbol of Molmol, the three-eyed elephant. Whenever Kaolla builds a gadget, or pulls out some of her currency, it has this motif on it. The third eye, the spirit eye in the center of the forehead, is a common symbol in Hindu and other eastern traditions, of course. The third eye sees the spirit world, or the dream world, which of course is so much closer in the Hinata apartments.
And when Kitsune, Kaolla, and Shinobu are spying on Naru and Kitsune, they are looking through, you guessed it, three holes. Coincidence? You decide!
I'm sure there's more, but my brain is wiped out from just writing all of this stuff down. The next entry on this topic will probably address specific storytelling and art techniques, and particularly what I can
But I'd love to hear any input you might have.