"Friended! with the Casagrandes" (or simply just "Friended!") is the first episode of the fourth season, the one-hundred-fiftieth episode, the eighth full-length episode, and the fourth season premiere of The Loud House. It is the sixth television appearance of The Casagrande Family.
At Great Lakes City, Ronnie Anne is prepared to spend her day at the park to do some skateboarding skills. Rosa also announces that the apartment above is available, and as manager of the building, she has to advertise for it. After greeting her family (while also assisting them a bit), Ronnie Anne heads out. When Ronnie Anne asks her local hot dog vendor to give her a hot dog with the works (at 9 AM), a girl behind her asks for the same. Further down the sidewalk, Ronnie Anne attempts to jump over a fire hydrant and succeeds. The girl from before meets up again, and asks Ronnie Anne if she can try, and she agrees. However, when doing the trick, she ends up rolling backwards and nearly crashes into a statue. When Ronnie Anne asks the girl if she has ever skateboarded before, the girl says that she hasn't, but has just recently moved here and wants to try everything new. Fascinated with her enthusiasm, Ronnie Anne introduces herself, and the girl introduces herself as Sid Chang.
While feeding the pigeons pieces of hot dog, Ronnie Anne and Sid exchange several pieces of personal information, like how Ronnie Anne is from Royal Woods and her father lives in Peru, while Sid's mother is a zoologist while her father works as a subway conductor. When Sid gets a text from her mother saying that she's done with something, she leaves.
Sometime later, Ronnie Anne exits the bodega and discovers Sid sitting on the front steps of the apartment, saying that her family is considering on living here. Realizing that they might be potential neighbors, Ronnie Anne pleads with Rosa to give the apartment to the Changs, but Rosa says that she doesn't have the power to do so, since she doesn't own the building. Ronnie Anne tells her cousins about the Changs, and they all express gratitude with them, since each one of them has a quirk that they like. Seeing how they all express the same desire for the Changs to live in the apartment, Ronnie Anne suggests that they try to dissuade any potential tenants from seeing the apartment. This ranges from Ronnie Anne and Carlota going around town to take down any flyers that Rosa put up, Bobby and Carl driving tenants away through several tactics and CJ keeping Rosa distracted.
When Rosa discovers that no one has come to see the apartment, she attempts to call the building owner, Mr. Scully, to consider giving the apartment to the Changs, but Mr. Scully calls her first, saying that he's sending someone over to look at the apartment, since he's friends with them, much to the dismay of Ronnie Anne.
As the kids start to mope at the fact that they might not get the Changs as their new neighbors because of the people Mr. Scully is sending over, Ronnie Anne comes up with a new plan: they'll make the apartment look as terrible as possible and she'll show them around instead of Rosa.
Then plan is set in motion by Carl opening the fridge, which catches Rosa's attention. When Carl hugs Rosa, he sneakily takes the apartment keys out of her pocket and hands it over to Lalo, who then hands it over to Ronnie Anne and Sid. When Carl passes out from eating too much food, Carlota distracts Rosa by asking for a fortune reading to see if a boy she likes likes her back. In the apartment, Ronnie Anne and Sid make the room look as terrible as possible by painting huge cracks and holes on the walls, gluing the windows wide open, and placing several stinky items in different rooms of the apartment. With their work done, CJ heads up to another resident of the building, Mrs. Kernicky, and Ronnie Anne sneaks the keys back into Rosa's pocket. At that moment, the people Mr. Scullyy sent over, the Reynolds, arrive to the apartment, and in another effort to distract her, Ronnie Anne and Carlota fake that Carl has gotten ill, and Ronnie Anne offers to show the Reynolds around.
Ronnie Anne shows Mr. and Mrs. Reynolds the apartment, and are horrified at its dilapidated state. The Reynolds are further discouraged when they hear clog dancing upstairs (courtesy of CJ), their inability to close the windows shut, the amount of animals living in the area and how the bedrooms are above the dumpster area. When the Reynolds leave, Ronnie Anne lies to Rosa by saying that the Reynolds weren't interested in the apartment because the building lacks an elevator. Suddenly, just when the kids and Sid begin to celebrate at becoming neighbors, Mr. Scully arrives and tells Rosa about what happened to the Reynolds. Mr. Scully, thinking that Rosa isn't taking care of the apartment, fires her as the manager of the building. This prompts Ronnie Anne to confess about her actions, saying she did it all for her friend wanting the place.
Sometime later, as Ronnie Anne sulks in her room, Maria and Rosa enter, and state while they are displeased with Ronnie Anne's actions, Rosa is glad that she still gets to keep her job as manager, and Maria tells Ronnie Anne that she must undo all the damage to the apartment. Ronnie Anne promptly fixes up the apartment (with a little help from Sergio) and Rosa tells her to come downstairs to welcome the new neighbors. At the entrance, a moving truck arrives, and the one sitting in the passenger seat is revealed to be Sid. When Ronnie Anne expresses confusion about why the Changs are here, Mr. Scully explains that he was moved by Ronnie Anne going through so much trouble for a friend, and found a way to fix both sides: he had the Reynolds live in another building he owns so that the Changs can live with the Santiagos, much to Ronnie Anne and Sid's happiness.