A lot of thought usually goes into a fan choosing their OTP...
Sorry, couldn't hold it in long enough. Okay, we admit it. One's OTP rarely has any thought into it going beyond the appearance of the characters involved. If they look cute together, we go for it. Like picking dolls to display on a shelf.
Sometimes, however, a couple is chosen due to their similarities. This is especially true if one's favorite pairing is separated by being in entirely different series, although not all theme pairings need involve such a Crossover Ship.
Examples of themes include:
- Similar character tropes (Badass Bookworm, Genki Girl/Keet, etc...).
- Similar ages outside the usual Competence Zone (if the series itself doesn't do that already).
- Similar powers or abilities (Elemental Powers especially)
- Two Ensemble Darkhorses or two Satellite Characters paired together.
- Token Minority Couple
- Identical or similar names.
- The characters are lookalikes.
That's love, baby! Okay, not really. But truthfully, people do get along better when they have something in common, so the idea isn't total bunk.
The basis of many a Crossover Ship.
- ILLUMINATED ships Jane from Tarzan and Captain Amelia from Treasure Planet. They're similar character: cultured women with 18th-19th century aesthetics and British accents.
- The Royal Protector pairs together Elsa from Frozen with Cassandra from Tangled: The Series because they fit a Lady and Knight theme: Elsa is The High Queen and Cassandra is her tomboyish Battle Butler.
- Pearl x Jet Link aka Cyborg 002 is pretty popular in some circles, since they have similar noses, hair color, and style (although Pearl's hair is lighter and shorter), and love to dance.
- While not as common as most others, Lilo Pelekai from Lilo & Stitch has occasionally been shipped with Mac from Foster's Home for Imaginary Friends due to a couple of similarities they have (being bullied, having a crazy non-human blue friend, etc.).
- Dipper (Gravity Falls) has been paired with Wirt (Over the Garden Wall), due to both being Adorkable nerds with goofy siblings. Dipper has also been shipped with Norman (ParaNorman), given they're both teens involved in the supernatural.
- In the Honor Harrington fanbase, this is the basis for Sonja Hemphill/Shannon Foraker. Lesbian technological geek geniuses? The idea was inevitable.
- Animal Crossing:
- Gulliver the seagull occasionally gets paired with one of the dodo birds, Orville and Wilbur, by fans, given that they're bird characters with a theme of traveling across the ocean.
- The villagers Audie and Whitney tend to be paired together a lot, romantically or platonically, due to them both being wolves with contrasting color palettesWhitney has a more wintry look compared to Audies summer vibe.
- Given how fond Mega Man (Classic) fans are of shipping Robot Masters with each other, this is a given. Some notable examples:
- Quick Man x Elec Man, because both of them are confident and speedy- not to mention Quick Man was canonically based on Elec Man.
- Wood Man x Plant Man, since they're both plant-based Robot Masters.
- Bubble Man x Splash Woman, since they're both aquatic Robot Masters that are more suited for water than land (Bubble Man can only move on land by jumping, and Splash Woman can't move on land at all due to being a mermaid).
- It is not uncommon for fans of Danganronpa to pair characters together that have similar ultimate talents or personalities. Some examples include:
- Kazuichi Soda and Miu Iruma (Both have ultimate talents related to building things and working with machines).
- Kaede, Ibuki, and/or Sayaka (All three have music related ultimate talents).
- Tsumugi and Hifumi (Both have ultimate talents relating to anime/manga and are both obsessed with it).
- Pokémon Sword and Shield:
- It's quite popular to ship Scorbunny with Buneary (as well as Raboot/Cinderace with Lopunny), due to both lines being based on bunnies coupled with their masculine and feminine designs respectively (especially the latter pair). While the Buneary line weren't compatible with the base game of Sword and Shield, they do show up in the Isle of Armor.
- Wooloo gets shipped with Mareep and Cottonee, as they're both based on sheep. Unfourtunately, Mareep isn't available in this game.
- On the human side of things, it's common to see Allister getting shipped with Acerola, since they are both young children who specialize in Ghost-type Pokémon, as well as both of them having a Mimikyu (Allister in-game, Acerola in the anime).
- Yo Kai Watch: Blizzaria/Drizzelda have a few shippers on deck, due to them both having control over bad weather (and of course, being cute girls).
- This is the basis of the Collectolon crack ship, which is infamous in the Aurora fandom.
- The Avatar: The Last Airbender fic Guide Me Home ships Ursa and Hakoda, the single parents of Zuko and Katara respectively.
- Teen Titans:
- Steven Universe:
- Back when they were first introduced, Lapis and Peridot were paired together often, simply because they were the only two Homeworld gems that had been introduced at that point. Though later episodes would provide shippers with much more reason to pair the two together.
- Bismuth and Jasper were paired together soon after the former's introduction, due to them both being big, buff gems with radical views.
- Aquamarine and Navy are sometimes paired together, due to both of them being fake cuties that manipulate and mock the Gems just for fun. It also helps that they both have adorable designs.
- Greg and Blue Diamond pretty much exploded in popularity after "Steven's Dream", due to their shared grief in losing a loved one and coming to something of an understanding over it. It's not uncommon to find AUs where Greg fell in love with Blue Diamond instead of Rose Quartz, or even some of Blue becoming Greg's Second Love.
- Hessonite and Emerald have supporters, mostly because of both being very high-ranked Gems with similar designs. They have never met in the show, and while Hessonite's appearance in Save The Light is considered canon, the events of the game she appeared in were never alluded to in the show.
- Spinel/Pink Pearl quickly became a popular ship following the release of Steven Universe: The Movie, partially because they've both received trauma, directly or indirectly, by the actions of Pink Diamond. Them both being pink and cute also helps.