The episode begins with Anais and Darwin observing Gumball attempting to become a Super Saiyan in the school corridor, managing nothing but extending his tail. As Anais is about to go to her class, her brothers ask her how and why she, a toddler, attends the same school as them. Anais is shocked and furious about the fact that neither of them know that she is in their own school and one grade above them, to which the confused Gumball replies that his class is the only one. Anais corrects him, and tells him that there are other students in the school as well. As Gumball and Darwin open their minds, they finally see that there are more students than they thought. Anais adds that some of them have even more interesting lives than Gumball. The skeptical Gumball questions who that might be.
The story now focuses on the story of Clare Cooper, a depressed and pessimistic girl, who is experiencing great sadness due to her father losing his job and their house, which forces them to move to Detroit. She decides to use her last day of school to say goodbye to her friends. However, Gumball and Darwin interfere with her life, and claim that they will fix everything for her, but she dismisses them, and insists that her ending will still be a sad one, so she proceeds saying goodbye to her friends. Anais criticizes her brothers for intervening with someone else's life just to be the center of attention, only to be dismissed by Gumball, who insists on helping Clare.
As Clare says goodbye to her friend, Wilson, Gumball and Darwin try to provide her with more optimism. Tired of this, Clare tells them to leave her alone, and storms off as Gumball continues to narrate her life. Later, Clare goes to say goodbye to her geography teacher. However, Gumball and Darwin once again interfere, and try to convince Clare that she can still have a happy ending. Refusing to believe them, she leaves in frustration. On the corridor, she bumps into Anais, who tells her that she should just allow them to help her despite their incapability to do so.
Finally, Clare is about to say goodbye to her love interest, Jared Dawson, only to encounter Gumball and Darwin talking to him, trying to persuade him to accompany Clare to Detroit. Angered, Clare yanks the brothers, slams them against the lockers and tells them that they have no right interfering with her life, and insists that her story is supposed to be a sad one with no happy ending, due to her belief that only bad things happen in real life, and that they do not live in a happy wonderland. The boys concede and sadly walk away.
After encountering Banana Joe, the brothers recall that they do live in an amazing fantasy world with a banana, a T-Rex, a ghost, a piece of toast, and a hairy slug. This makes them believe that the world is whatever they want it to be, and proceed with giving Clare a happy ending. Later on, Clare enters the bus to the airport while depressingly narrating her life, and seemingly giving herself a sad ending. Suddenly, Gumball and Darwin show up mounting Tina, who pushes the bus onto its side. They help Clare to her feet, and provide her with a happy ending, where her father was given a new job at the Rainbow Factory, her house was bought back by Mrs. Jötunheim, and Clare and Jared are crowned prom king and queen of Elmore Junior High. Clare is speechless.
The So-Called World of Clare is a reference to the 1994 TV show, My So-Called Life. The three main characters are named Clare, Jared, and Wilson because that series starred Claire Danes (note the different spelling,) Jared Leto, and Wilson Cruz.
Tina stopping Clare's bus is a reference to the scene in The Lost World of Jurassic Park, where the T-Rex buck chases and destroys a bus during it's rampage through San Francisco.
The music that plays during the "Happy Ending" is "Semper Fidelis," which was composed by John Phillip Sousa.
During the highway scene, various characters disappear and reappear.
[The episode starts in the school. Gumball and Darwin are in the hallway, some of their classmates are chatting nearby]
Gumball: All I have to do is harness the power within and I'll turn into a Super Saiyan!
[Gumball takes a deep breath, exhales then screams angrily. Everyone hears and glances at him from afar. Anais walks by]
Anais: Is he still trying to turn into a Super Saiyan? Stop, you're gonna pop something important.
Gumball: [Still screaming] ALL I HAVE TO DO IS BELIEVE IN MYSELF!
[As Gumball screams, his faces turns red and his tail elongates]
Gumball: [Stops screaming] That's not quite the transformation I was hoping for.
[Gumball inhales deeply so his tail starts retracting]
Anais: Anyway, I'm gonna be late to class.
[Anais tries to walk away but she is stopped by Darwin]
Darwin: Anais, can I ask something?
Darwin: You know how you're like, a baby, but you're at school with us. How does that work?
Gumball: Yeah, it's totally unrealistic.
[Gumball inhales. His tail makes a 'boing' sound and goes back to normal]
Anais: Are you- [Drops book in disbelief] I... Wha... Ack... Wha... Eh... Ah, eh, ah, ack... ARE YOU KIDDING ME?!
Darwin: I'm not sure what you're upset about.
Anais: The fact that neither of you know that your sister, who you live with, is in a year above you in your own school!
Gumball: What are you talking about? Look around you, mine's the only class in Elmore Junior High.
Anais: Gumball, no it isn't. The world doesn't revolve around you.
[Gumball spins around]
Gumball: Yes it does. Look, it's happening right now!
[Anais stops Gumball from spinning]
Anais: Just try for one minute to see that there're other kids in the school. [Whispering] Open your mind, open your mind...
[Gumball's head splits in two, showing his brain. Anais puts it back together]
Anais: Not literally. Open your mind, open your mind...
[Gumball's pupils grow]
[The scene magically reveals other students and teachers walking around the hallways. Gumball and Darwin begin to hallucinate psychedelically when they realize they are not the only students in school]
Gumball: [In a warped voice from the hallucination] There...are...others!
[The hallucination stops abruptly]
Anais: Yes! And believe it or not, some of them have even more interesting lives than you.
Gumball: Pssshhh! Like who?
[A sitcom-style opening plays, introducing Clare, Jared, Wilson and Mr. Corneille as the protagonists of "The So-Called World of Clare"]
The So-Called World of Clare
[The focus is now on a green-haired girl who looks depressed. She is holding a book and removing pictures from her locker]
Clare: [To herself] My name is Clare and today is the worst day of my life. My dad has lost his job, we've lost our house and now we're forced to move back to Detroit. I only have one day to say goodbye to the ones I love. One last day to say goodbye [Closes locker] to my so-called world.
Gumball: [Offscreen] "But luckily, two strangers were about to change my life forever."
[Clare turns around to see Gumball leaning against a locker. Darwin is dancing and pointing at him, occasionally mimicking his smug gestures for emphasis]
Gumball: "That's right: Gumball and Darwin. Gumball was devastatingly, inhumanly beautiful, his face is like a classic painting crafted by an old master."
Clare: Uh, who are you?
Gumball: "I didn't realize it yet, but these two were the true heroes of my story."
Clare: [Sighing, she turns back and opens her locker again][To herself] The first person I needed to say goodbye to was my only true friend, Wilson. [Takes a paper from her locker and unfolds it to reveal a picture of Wilson] Wilson always struggled with his identity-
Gumball: "But Gumball and Darwin would help Wilson find himself."
Clare: [Out loud] It was going to be a tearful goodbye-
Gumball: [Raising his voice] "But I knew that with the help of Gumball and Darwin-"
Clare: [Raising her voice] Better get to it now, while I still have the strength in my heart!
[Clare slams the locker door shut and walks off]
Gumball: Dude, that girl is crying out for our help.
Anais: [Walks up to Gumball and Darwin] No, she isn't. You are only getting involved in her story so you can be the center of attention and, as usual, you'll ignore anything that gets in your w- [Gumball starts focusing, making Anais fade away] No, no no, don't you dare make me disappear!
Gumball: Like I was saying: let's get this girl all the help she needs to stay here in Elmore! [Anais, now invisible, kicks Gumball] Ow!
[Clare is sitting at the stadium with her friend Wilson]
Clare: Oh, Wilson. Where is the "good" in "goodbye"?
Gumball: [Whispering offscreen] It's just before the "bye"!
Wilson: I don't know what I'll do without you. The cheerleader in me is so, "Give me an 'S', give me an 'A', give me a 'D', what does it spell?" Sad... But at the same time the goth in me is all like "Ugh, whatever," but the football player in me is all like [Flexing his pecs, screaming] and the majorette in me gives a low, sad blast on his trombone.
Darwin: [Whispering offscreen] I thought it was actually going to make the noise.
Clare: [Turns to Gumball and Darwin] Ah, leave us alone! Don't you get it? This is not about you!
Gumball: Not about Chu?
Darwin: What does that mean?
Gumball: I don't know, it sounds Cantonese.
Clare: I said: this is not about you.
Darwin: Not a bad chew...?
Clare: Not about you!
Gumball: [Shrugs] I'm still not getting it.
Clare: Argh! [Turning to Wilson] Goodbye.
[Wilson waves goodbye to Clare while she storms off]
Gumball: "As I walked into the distance I realized that whilst I had lost one friend, I had gained two, who were far superior to the other one. I mean, what was he supposed to be, anyway?"
Clare: [Screaming] Can you at least let me voice my own thoughts?!
[Cut to Clare opening her locker]
Clare: Next I had to say goodbye to the person who told me everything I know... [Takes a geography book from her locker] ...about geography: Mr. Corneille.
[Clare enters a classroom where she finds Mr. Corneille sitting at his desk]
Moonchild Corneille: Ah, Miss Cooper. Like Shakespeare once said: "Parting is such sweet sorrow". And the capital of Sweden is Stockholm. Facts.
Clare: I wanted to thank you, Mr. Corneille.
Moonchild Corneille: If you only remember one thing I've taught you it's this: "Question everything".
Moonchild Corneille: No, don't question that. Question everything except that.
Clare: So it's "Question everything unquestioningly"?
Moonchild Corneille: Yes, I think.
Clare: But, what am I going to do without you?
Moonchild Corneille: As long as you carry that book I gave you I will always be watching over you.
Clare: Like, you mean in spirit?
Moonchild Corneille: No, turn it over.
[Clare turns the book, revealing a picture of Mr. Corneille]
[Clare starts crying. She is interrupted by Gumball who is aiming a fan directly to her face]
Clare: What are you doing?!
[The fan stops]
Gumball: [Softly] We're drying your tears.
[The fan starts again. Clare throws it out the window]
Clare: What do you want from me?!
Darwin: We wanna help. There's no reason for you to leave Elmore.
Clare: There's nothing you can do about it. And like I said before: this is not about you!
Darwin: [In Cantonese] We don't speak Cantonese!
Clare: [Screaming in frustration]
Gumball: See, the problem here is your attitude towards life. Darwin, you'll be Clare, I'll be life.
Darwin: Ok. [A green wig appears on Darwin's head with a 'pop' sound]
Gumball: Life is giving Clare a hard time. [Slaps Darwin] What is she doing about it?
Darwin: [Whining in gibberish]
Gumball: Let's try that again, but with a more proactive attitude. [Darwin blocks Gumball's hit and swiftly throws him out the window. He walks back into the classroom] Now, do you see the difference between fighting the odds and just moping about?
Clare: Mr. Corneille, say something!
Moonchild Corneille: Uh... Brussels is the capital of Belgium?
Clare: Ugh! I do not mope! [Walks out of the classroom and into the hallway]
Anais: [Bumps into Clare, who trips and falls with a loud thump] Sorry, Clare! I was hoping you'd bump into me for dramatic effect, but I didn't count on how small I was and... anyway, what I wanted to say was... [Whispering dramatically] Let them help you.
Clare: But they seem really bad at helping.
Anais: Oh, they are! But they're even worse when they don't get their own way.
[A dramatic chorus sings and thunder can be heard as Gumball and Darwin stare at Clare through the classroom door. When Clare turns back, Anais is nowhere to be seen]
Clare: [Gasps] She disappeared!
Anais: No, I just got around the corner for dramatic effect!
[Clare opens the door to the food court]
Clare: [To herself] So now it was time for the hardest goodbye of all, Jared, the love of my- [Out loud, frustrated] Oh, come on!
[Gumball and Darwin are sitting at a table with Jared]
Darwin: Jared, you've got to trust us!
Gumball: You have to follow Clare to Detroit, ok?
Darwin: But not straight away.
Gumball: Let her get all the way to the airport, then as she waits to board the plane and the last call for the flight is announced, you run to the airport in slow motion, you grab her hand, she sees the bracelet - the bracelet she made for you as a symbol of your love.
Jared: Sorry, do I know you?
[Clare picks up Gumball and Darwin and throws them into the hallway, clearly annoyed]
Clare: Listen: this is not a story with a happy ending, okay? It's a story I write on my diary using my tears as ink. [Darwin hands out a pen, which Clare smacks away] You think you live in some amazing magic wonderland where everything has a happy ending? Well, the truth is: this is real life, and bad things happen in real life.
[Gumball and Darwin walk away with a sad expression. Banana Joe approaches them]
Banana Joe: Ah, why so sad?
[Banana Joe lifts the bottom of his peel, dances can-can briefly then moons Gumball and Darwin while making a fart sound with his mouth]
Gumball: Wait a minute, this here is a talking and dancing banana who somehow has a butt. We are in a school with a T-Rex, a ghost, a toast, and whatever Principal Brown is. Now who dares to say this world isn't amazing? The world is what you make it!
Darwin: But she doesn't want our help.
Gumball: Do you want to be a spectator in life or do you wanna play a part?
Darwin: Wasn't this about helping Clare?
Gumball: Yeah that too. Now let's go and give her a happy ending, whether she likes it or not.
[Gumball and Darwin run off]
Banana Joe: [Nods in approval] Wait, why do I have a butt?
[Clare gets on the bus in rainy weather. She sits down and stares out the window, reflecting on her past in Elmore]
Clare: [To herself] My eyes dropped pearls of sadness as I saw my past drift away into nothingness. I saw the swings where Wilson and I shared so much, the park where Jared-
Gumball: [Heaving as he sits on Darwin, who is running after the bus] Stop the bus! We fixed everything! Stop the bus!
Clare: -where Jared gave his heart to me. The picket fences on the streets - [Darwin jumps over a fence] streets I walked a thousand times - our old house, its "For Sale" sign mocking me from the front lawn.
[Gumball's head hits a "For Sale" sign and he falls off Darwin]
Clare: I looked at my friends' houses, houses in which I'd never again laugh, in which I'd never again cry.
[Gumball and Darwin are flying on Bobert's back and trying to catch Clare's attention]
Clare: But what if I gain from this loss? And what does that mean?
[Bobert hits a clothes line, launching him offscreen. A loud explosion can be heard]
Clare: Maybe it doesn't mean anything. Anything at all.
[Gumball and Darwin now ride Clayton in his horse form, waving at Clare. She looks away from the window, tearfully. They crash into a van]
Clare: The only thing left to do is to stare at the rain. So I guess this is it. Goodbye Elmore, goodbye friends, goodbye life.
[Credits begin to appear on the window, interrupted by Nicole's car driving by. Anais points to something offscreen. A loud rumbling sound is heard]
[The view suddenly shifts to Tina Rex, roaring loudly and chasing Clare's bus. Gumball and Darwin wave at Clare, riding Tina's back as she headbutts the bus]
[Tina headbutts the bus again, this time flipping it over. She takes Clare out of the bus, then Gumball and Darwin help her back on her feet]
Clare: What's going on?!
Gumball: Only the biggest happy ending of your life!
[Gumball, Darwin and Clare turn to a crowd while a cheerful marching band track plays. Anais shrugs]
Gumball: [Shouting in megaphone] You don't need to leave Elmore, we fixed everything for you! [Flashes an eerie smile with human-like teeth]
Clare: But how could you ever fix-
Gumball: FIRST! We got Masami to ask her dad to give your dad a new job as an engineer at the Rainbow Factory!
Clare: But my dad isn't qual-
Gumball: Qualified? Heh! You don't need a qualification if you got a made-up magic job. [In megaphone] Are you feeling happy Mr. Cooper?
Mr. Cooper: [Hesitatingly] Yes?
Gumball: I think what he meant was: [In megaphone] YEAH!
Clare: But what about my-
Gumball: Did you just say "house"?!
[Gumball's irises grow wide with excitement, he shakes Clare back and forth and climbs on her back to show a vision of Mrs. Jötunheim standing in front of a house with a "Sold" sign]
Gumball: Well, Mrs. Jötunheim used her broomstick to find the end of the rainbow where she stole a pot of gold from a leprechaun, which she used to buy it back! [The vision vanishes] And now, don't forget your old buddy Wilson, well when he saw a cat and a goldfish riding a T-Rex down the freeway he realized that maybe he wasn't so strange after all. [In megaphone] RIGHT, WILSON? Riiight! And the cherry on top: [Screaming louder and louder in the megaphone while Darwin pushes Jared next to Clare] Jared and Clare, you are hereby elected the Prom King and Queen of Elmore Junior High!
[The crowd cheers and fireworks go off as Jared and Clare are crowned]
Jared: [Whispering, visibly unsettled] Just go with it, these people are insane!
Gumball: [Still shouting in his megaphone] Take that! Mega-happy ending, thank you everyone, thank you Elmore! BOOM!
[Gumball drops his megaphone and starts dancing frantically next to Clare. Everyone cheers, the music eventually ends - as does the episode]