The world of anime is renowned for its many conventions, tropes and archetypes. One of the most common types is the "gap moe," a broad term describing any character whose appearance, behavior, interests and/or lifestyle contrast with the initial impression that they make. Tsunderes are, in fact, part of the larger gap moe umbrella, but the term can take other forms, too.
"Moe" is a broad Japanese pop culture term describing a fictional character who is the object of intense endearment. When a gruff-looking character is actually warm and fuzzy inside, that's a veritable wellspring of unexpected cuteness, and thus, gap moe is born. A handful of well-known anime characters, major and minor, are excellent examples of this.
The Theory Of Gap Moe
Anime fans have theorized deeply on this topic online, and a few distinct trends of gap moe have emerged over time. Arguably, the most common and endearing form is based on personality, and that is exactly where the tsundere archetype comes in. Such a character has two modes: cold and aloof, and warm and fuzzy. Which side will they show? That depends on the situation and the other party, and this hot/cold dynamic can make the character feel complex and deep, especially when the archetype is done just right. A tsundere isn't entirely jaded or happy-go-lucky; instead, they have discretion, and sometimes, they can't even help it at all.
It's instantly lovable when an aloof character's icy exterior is shattered by a new friend or love interest, and the tsundere thinks "Whoa! How did this happen? What are these sudden feelings?" Then the outside party has to "earn" the tsundere's sincere affection and attachment, creating a fun challenge. And even the tsundere might struggle with his or her own nature.
Gap moe can also take a superficial form: the character's appearance/lifestyle. After all, a character's appearance will be influenced by factors such as their profession, sex, age, lifestyle and more, as well as their general health. First impressions count for a lot but can also be deceiving, and discovering the gap moe character's other side can be a thrilling (and charming) experience.
This can take the form of the "punk with a heart of gold" type, and that's certainly not limited to the anime world. Many works of Western fiction do this too, with even the likes of Han Solo fulfilling this archetype. Han was a gruff and self-centered rogue at first, but then his heroic side emerged, and he risked his life to save Luke Skywalker during the Death Star battle (and Leia fell in love with him later). Han would feel right at home in anime as a gap moe character.
Examples Of Gap Moe Characters
Many anime characters can be categorized as gap moe, and not all of them are the protagonists or even secondary characters of their respective series. An otherwise forgettable character can stand out, such as the pro hero Gun Head from My Hero Academia. In one scene, Ochaco Uraraka trains with him to learn CQC techniques, then gets a phone call from Izuku, her personal role model. Gun Head, despite his terrifying appearance and martial arts skills, blushes and puts a hand to his "mouth," asking if Ochaco is on the phone with her boyfriend. Who knew he had such a soft side?
A similar character is Bleach's Kenpachi Zaraki who, in spite of his brutal personality and appearance, has a tender paternal side when it comes to his Lieutenant, the young Yachiru Kusajishi. Kenpachi is a gap moe character based on personality and appearance, so his doting on Yachiru really shines. Tatsu from The Way of the Househusband, a scarred ex-mobster who runs a lovely household with great care, is also gap moe in both appearance and personality.
Katarina Claes of My Next Life as a Villainess fame is an appearance-based and role-based gap moe. She's not a tsundere, since her personality is consistent. Instead, she looks like an arrogant and bratty rich girl, and the original Katarina was a bully who flaunted her power and influence. But this reborn Katarina is a kind, compassionate and humorously dense girl who puts other people's happiness first, and her only stake in all this is to prevent her own doom. Otherwise, this Katarina is definitely Best Girl, and the original Katarina Claes would be shocked and outraged.
Lastly, Takeo Gouda of My Love Story!! is a classic appearance-based gap moe character, a hulking high school boy with a broad chest, thick lips and a blunt face. He looks like a cheap bully, yet he is anything but. Takeo's gap moe nature is the selling point of the entire franchise. He underestimates his own appeal when he presumes that his crush, Rinko Yamato, is more interested in the typical "pretty boy" Makoto Sunakawa than him. To his pleasant surprise, he was wrong -- Rinka loves Takeo for his gentle, warm and trusting personality, no matter what his brutish appearance may suggest. The visual contrast comfortably complements how well the two characters get along. Even though they look like beauty and the beast, they are kindred spirits on the inside. And that's what counts the most.