The episode begins with Marco and Star being forced to retreat into the Diaz's backyard shed, under attack by much more of Ludo's henchmen than usual. As Marco starts on a bizarre project with the items of the shed, he confesses that the situation is all his fault.
Flashback to earlier in the week, when Marco has suffered an incredibly bad day. Being the friend she is, Star does her best to try and cheer Marco up, and eventually makes him laugh.
Sometime later in the week, Star meets Echo Creeks' resident delinquent/musician, Oskar. She gives him her number (actually Marco's; she likes his ringtone more), and eagerly awaits his call. When he doesn't call, Star quickly becomes depressed.
Marco attempts to cheer Star up to return the favor, but his attempts are much less effective (and dangerous) than what Star has done. Stumped, he eventually realizes that Star is at her happiest when she's fighting monsters, so he takes her wand and baits Ludo's minions with it.
Unfortunately, he ends up attracting way more monsters than he originally anticipated, leading to their present situation.
Armed with makeshift armour, Marco and Star promptly engage the monsters—and simultaneously show that all of Marco's hard work has been for completely nothing. Oskar calls in the middle of the fight, and an ill-timed attack by a minion quickly ends things when Star gets angry over being interrupted while talking to him.
Star, happy that Marco had gone to such efforts to cheer her up, hugs him, and the two share a tender moment... then realise they're stuck together with the syrup she summoned.
Tropes:
- All Girls Want Bad Boys: Star is especially intrigued when Principal Skeeves tells her Oskar has "a record".
- Berserk Button: Do NOT interrupt Star when she's on the phone with her crush, lest you want to be covered in a tidal wave of syrup.
- Boredom Montage: The montage of Star waiting for Oskar to call her back.
- Brick Joke: The guy on the bicycle who stopped to laugh at Marco's "I Kissed a Ninja" t-shirt shows up again at the end of the episode to point and laugh at Star and Marco when they get stuck together.
- Cheer Up Episode: As the title suggests, Marco tries to cheer up Star to repay her earlier kindness.
- Comically Missing the Point: Star sees Marco chasing after the school bus, but thinks he's "in the zone" and doesn't realize that she should probably tell the bus driver to stop.
- Continuity Nod: Star apparently kept her failed math test from "Match Maker".
- Does This Remind You of Anything?: Star gets a little too into a fantasy involving her and Oskar, leaving her nibbling on her wand in a dreamy fashion while she makes noises of pleasure. It also doesn't help that Marco splatters a bucket of red paint on the wall while she's fantasizing.
- Dreadful Musician: Oskar's keytar playing causes every Earth native in the vicinity to scream and writhe in pain. As she is from Mewni, Star actually thinks it's good.
- Embarrassing Ringtone: Marco's ringtone is "Space Unicorn" by Parry Gripp. He claims "It's supposed to be ironic."
- Epic Fail: Marco's second attempt to make Star happy had him on a shopping cart on a rocket wearing a sombrero with fireworks, that ends with fireworks going off like crazy, a sword falling on the floor, and water flowing down the steps with Marco in the stream.
- Full-Name Ultimatum: When Marco is too busy constructing the makeshift armor to answer Star's question about what's going on, she eventually yells out "MARCO DIAZ!" in frustration.
- Gone Horribly Right: Marco wanted to attract some monsters for Star to fight in order to cheer her up. He ended up bringing way too many monsters to the Diaz home.
- How We Got Here: The meat of the episode is explaining why Star and Marco are running from a pack of Ludo's minions.
- Humiliation Conga: It starts with Marco missing the bus, and only gets worse from there.
- Imagine Spotting: Marco complains that Star is daydreaming in the middle of his flashback.
- Improvised Armor: In-between flashbacks in the episode, Marco uses objects in the tool shed he and Star are holed up in to make armor to wear against Ludo's mooks outside. Once he puts the finishing touches on both Star's and his own, he is simply pulled out of it by a Mook.
- Non-Ironic Clown: Marco tries dressing up as a clown to cheer up Star, but his presentation (sneaking up on her in a dark room with a Scary Flashlight Face) comes off as a Monster Clown.Marco: I thought you liked clowns, sorry!
- Remember the New Guy?: Ludo claims that the new henchmen in the episode (like Man-Arm and Spike Balls) have always been present. The monsters themselves claim they were just in the back lines.
- "Shaggy Dog" Story: Marco is effortlessly yanked out of the makeshift armor he spent the whole episode building.
- Sticky Situation: The episode ends with Star and Marco stuck together with syrup.
- Swallowed Whole: While trying to cheer up Marco, Star ends up getting briefly eaten by a giant catfish-like creature.
- Trauma Conga Line: Marco suffers one to start the events of the episode. He chases after the bus, gets hit by its Stop sign, then gets his shirt stuck in the door that rips, revealing a humiliating T-shirt. To top it all off, it's Picture Day, and Jeremy was going to "humiliate" him but got beaten to it, and because Marco was distracted, he breaks his crush's skateboard.
