We open with Lincoln informing us that this is a "special" episode (so he likely has all his sisters, although it's not outright stated), and it is unusual, even by their standards. Lisa is curious, so he clarifies that it introduces an extra Loud, who is Lincoln's twin brother. Lola expresses displeasure at the idea of "another Lincoln", but Lincoln points out that a twin is not a clone, and they go onto the story, which is aptly titled Lincoln's Twin Brother.
It begins at four AM on a Saturday morning, but the brother, whose name is revealed to be Lio, is already up and about. It turns out that he wants to be first to buy a new comic book at the store and is leaving early to avoid a rush of customers. Fanfic Lincoln reveals that Lio is interested in anime and manga and styled his hair after his favourite anime villain.
Lori (the real one) calls Lio a weeb. Lincoln points out that liking anime doesn't make you a weeb, and Lori agrees, but states that styling your hair after an anime character does make you a weeb. Then, Lio puts on an anime longcoat, which Lori takes as further evidence of his weeb-dom. She reveals that she likes some anime, but doesn't base her entire personality on it. Lynn then critiques Lori's taste in anime, preferring more action-oriented anime, and the two argue. Then, Lucy reveals that she likes an anime about vampires that she is too young for.
Lio is about to head out, when he hears a sniffle. He fears being grounded by Rita (even though the real Rita doesn't ground her kids for waking up too early). However, fanfic Rita is absent. Lio hears the TV and is surprised, but brushes it off, until he hears crying. It's revealed that Lio hates hearing people being sad, which is described as his "weakness", even though, as the real Lisa points out, most people dislike hearing people being sad— that's what empathy is.
He goes into the living room to find that it's Luan who's crying. The real Luan wonders why, and Lori reveals that Lana has recently cried about snakes not having arms. Lio is shocked because apparently Luan is always happy (even though, as the real Luan points out, no one is always happy) and asks her what is wrong. Fanfic Luan claims that she was watching an emotional movie, but somehow Lio can tell that's a lie.
He convinces her to open up, despite her believing he wouldn't understand, and it turns out that she is sad because she fears being seen as obnoxious. The real Loud siblings tell Luan that they don't find her obnoxious, or at least not moreso than most siblings annoying each other.
Fanfic Luan goes on, saying that she thinks her siblings don't love her, and that she's been worrying about it for a few months, even considering running away. The real Luan reveals that she too has occasionally thought of running away, scaring her siblings. Leni then gives Luan a hug that is so powerful it causes an explosion and puts the latter into a daze.
Fanfic Luan reveals that she isn't very close to Luna and took up comedy to deal with loneliness. The real Luna points out that she and Luan are actually pretty close due to both being performers. Lio can relate— he doesn't trust Lincoln to cheer him up when he's sad, and he has very few friends due to his shy personality. He then reveals that his interest in anime and manga is also to deal with loneliness.
Lio then talks about his and Lincoln's first day of school, and we get a flashback. A kindergarten-aged Lincoln and Lio return home from school, crying and not wanting to go back. Kindergartener Lio even thinks he might die if he goes back to school. Luan asks what's wrong, and the boys reveal that their classmates teased them for their white hair, calling them old men and albino freaks.
Back on the couch, Lynn points out that kindergarteners don't generally know the word "albino", but Lily does. Fanfic Luan starts telling jokes to cheer the boys up, which the real Luan rates.
The next morning, kindergartener Lio is still scared to go to school, so Luan gives him a pep talk about times he was brave, and has him wear a cape. Lori (the real one) thinks that's a recipe for more teasing, but it works. He also picks up a manga at the library, starting his interest in Japanese culture.
We then go into the present briefly, where fanfic Luan is surprised that Lio remembers the incident. Another flashback shows a third-grade Lincoln and Lio arguing. It turns out that Lincoln released the mice his teacher wanted to dissect (though only as a joke and not to save them) and Principal Huggins suspended them both for three days due to not being able to tell them apart (apparently, Lio is no longer wearing a cape). Third-grader Lio is frustrated at being confused with Lincoln, so Luan suggests changing his hair and clothes, leading to Lio dyeing his hair black.
The hair dye came from Luan, who wanted to prank Lori or Leni, even though the real Lori wouldn't mind having her hair dyed black, and the real Leni would like it. The flashback ends, and the real Lincoln wonders why Lio didn't forgive his fanfic counterpart. Lucy points out that forgiveness is something you earn and doesn't happen immediately, but Lincoln points out that a three-day suspension isn't that big a deal.
Lio then goes on to compliment Luan for cheering him up when he's sad, and Lincoln expresses surprise at Luan being such a major character. The real Luan points out that the previous OC protagonist, Nolan, had a favourite sister too: Leni.
Fanfic Luan is finally feeling better, and Lio decides to stay to make sure she really is feeling better, reading the manga online instead of buying it at the store. The two watch a reality TV show, and several hours later, Lio draws a manga-stylised comic with a theme of family. He then later gets given the manga he wanted (either by Luan or Lincoln probably).
With the story over, Lincoln asks his sisters what they thought of Lio. Lori likes his individuality, both she and Lynn want to see more of his day-to-day life, Lola still only wants one brother, Luan actually wants Lio around, and Lucy wouldn't mind having another "tormented artist" around.
This episode provides examples of
- Adaptational Jerkass: Apparently, the fanfic versions of the Loud siblings all don't mind seeing/hearing people sad, and they view Lio's empathy as his "weakness".
- Adaptation Relationship Overhaul: The fanfic versions of Luna and Luan are distant, while the real Luna and Luan are close.
- Age-Inappropriate Art: Lucy watches an anime that she is apparently way too young for.
- Albinos Are Freaks: The kindergartener Lincoln and Lio's classmates call them "albino freaks".
- Alternate Universe Fic: This story follows the premise of "What if Lincoln had an identical twin?".
- Big, Stupid Doodoo-Head: Lincoln reveals that in second grade, there was a boy in his class who called him "powdered sugar", but he wasn't very good at being a bully because it's not that mean.
- Boomerang Bigot: Lynn, despite being a girl, disses Lori's favourite anime by calling it "girly".
- But You Were There, and You, and You: Implied. Lio's comic he draws features a ponytailed heroine.
- Continuity Nod: Luan remembers Nolan, who appeared in Lynn's Bruised Hand from Episode 11, and Nolan's Birthday from Episode 14.
- Cool Big Sis: Lio looks up to Luan because of her cheering him up when he was sad, and inspiring his life choices.
- Copycat Mockery: Lori and Lynn, while arguing over anime, mimic the characters of the other's favourite anime to make them seem unflattering.Lynn: "Ooooh, I'm gonna beat all those big scary monsters with the power of love and friendship and butterfly kisses!"Lori: "Grrr, power level this, power level that, I can solve every problem by punching it really hard!"
- Dark Fic: While the flashbacks aren't that dark, the story as a whole is pretty dark, with Luan feeling useless and unloved.
- The Ditz: The fish in the third-grade Luan's joke in the story forgot how to swim.
- Don't Explain the Joke: In the story, the third-grade Luan claims that a joke isn't a joke if you need to explain it.
- Even Nerds Have Standards: Lori and Lynn like anime, but they agree that styling your hair after an anime character makes you a weeb.
- Evil Is Cool: In-Universe, Lio's favourite anime character is a villain.
- Fingore: One of the younger Luan's jokes in the story involves a girl breaking her finger.
- Free the Frogs: Played with. In the story, the third-grade Lincoln saves some mice from dissection, though as a prank and not to save them.
- Hidden Depths: Lori, Lynn, and Lucy watch anime, and Lily knows what an albino is.
- Little "No": Lio whispers, "No! No! NO!" when Luan reveals she feels unloved.
- Little Professor Dialogue: Lincoln and Lio's kindergarten classmates know the word "albino", as does Lily (though she pronounces it "abano".)
- Near-Death Experience: Apparently, Luan has a tape in her collection called "Lincoln almost dies".
- Nice Guy: Lio's defining trait besides his being, as Lori puts it, a weeb, is his empathy.
- Noodle Incident:
- Lana once cried about snakes, and it had something to do with them not having arms.
- When the sisters give examples of their siblings' annoying behaviours, Lisa reveals that she was beaten at chess by an unknown sister, who Lisa is certain cheats.
- Luan apparently has a video tape called "Lincoln almost dies".
- O.O.C. Is Serious Business: Lio is scared to see the normally cheerful Luan sobbing.
- Original Character: Lio is not a canon Loud House character.
- Out of Character: Implied. Lio fears being grounded by Rita for waking up too early, even though the real Rita shows no ill-will towards her kids waking up too early.
- Pun:
- In the story, a third-grade Luan makes jokes about a sandwich cooking when it's "bacon" lettuce and tomato, a fish "floundering", light travelling faster than sound because someone can appear "bright" until you hear them speak, stairs being "up to something", someone breaking her finger but being fine "on the other hand", and the opposite of Slim Shady being Thicc Sunny.
- In the present, fanfic Luan makes a joke about how 19 and 20 got into a fight and "21".
- The Runaway: Discussed. Both fanfic Luan and the real Luan have thought of running away, but never actually done it.
- Sad Clown: Downplayed for fanfic Luan. Usually her comedic persona is genuine, but over the past few months, she has been feeling unloved, and when she initially took up comedy, it was to deal with being lonely.
- Say My Name: Lincoln exclaims, "Lola!" when Lola calls Luan annoying.
- Shared Family Quirks:
- Fanfic Lincoln and Lio both read comics, although Lio reads exclusively manga. Lincoln has read manga in canon, but his interest in comics is more culturally varied.
- A dark example— Fanfic Luan and Lio both chose their hobbies to deal with loneliness and feeling unloved.
- Shout-Out: Lori mentions that Lana once cried about snakes because they don’t have any arms.
- Shrinking Violet: Apparently, Lio is shy and has hardly any friends.
- Silent Treatment: When the third-grade Lio is angry at Lincoln, he refuses to talk to him.
- Single-Minded Twins: Discussed. Lola is initially concerned that if Lincoln had a twin brother, it'd be like having two Lincolns, but he points out that it wouldn't necessarily be the case.
- Smart People Play Chess: Lisa apparently plays chess with another sister (unstated, but probably Lily since the others were complaining about their roommates) and, upon losing, suspects her of cheating.
- Stepford Smiler: Downplayed for fanfic Luan, who usually is happy, but when she does get sad, she gets very sad but pretends to still be happy.
- Stock "Yuck!": The kindergarten-aged Lio promises to eat his vegetables, suggesting that he dislikes eating vegetables.
- Superheroes Wear Capes: In the story, Luan has kindergartener Lio wear a cape so that his bullies would see him as a superhero, and, despite Lori's doubts, it works.
- Sweetness Aversion: In-Universe, Lynn thinks Lori's favourite anime is too sugary, with its reliance on "the power of love and friendship and butterfly kisses".
- Tears of Joy: Fanfic Luan cries tears of joy after Lio's pep talk.
- Theme Twin Naming: Downplayed— the brothers are Lincoln and Lio, but considering all the Loud siblings have "L" names, it's not really that big a deal.
- Wingding Eyes: When Leni hugs Luan, the latter gets heart-shaped pupils and rainbow-coloured sclerae.
- You Are Grounded!: Discussed. Lio fears being grounded by Rita for waking up too early.
