[3][4] The series centers around a large Mexican-American family living in the neighboring Los Angeles town of Hacienda Hills.

Told through the diary of eccentric 9-year-old (later 10-year-old) Tater Ramirez-Humphrey, the series centers on her as she discovers the "it factor" that makes her special alongside her cousins, consisting of Cousin Bud, Big Nacho, Lita, Tere, Tabi, Toñita, Scooter, Lot Lot, Gordita, Nachito, ChaCha, and Lucita, who moved in with her for the summer as she prepares for her upcoming tenth birthday and tries to figure out her "final form".

[1] Another recurring character is Hector, the local street vendor of different foods who never utters a word yet and is said to be fluent in Spanish and French.

Tater Ramirez-Humphrey plans to spend the entire summer discovering what her "final form" will be, despite the cynicism of her younger sister Nellie and the indifference of the rest of her family.

Tater wants to join the "10-under-10" for Biz Kid Magazine and attempts to plan out some kind of talent to show off so that she can send it to the publication.

Every attempt at trying to give or tell him something results in him rushing back to the hardware store even after getting some advice from Bibi who is working out with Pop.

Her sister Nellie arrives and cheekily threatens to expose her hiding spot or move in herself, only to get stuck in the floorboards and with the garage possum loose.

Overcome by her love for her sister, Tater rescues her and Nellie decides to keep her hiding spot a secret, admitting that she similarly likes to meditate to get away.

Tater is embarrassed over the fact that she cannot understand Spanish very well when she is with her primos at a churro stand run by a Spanish-speaking vendor named Hector.

The primos are shocked by this decision and try to force her to learn Spanish, trapping her in a room (a lá Saw) and having her go through various tasks, showing that she does know some of the language.

The two decide to play detective and recruit Lita to help search for clues by asking the eldest primos: Cousin Bud, Big Nacho, and Tabi.

They bring the primos together and deduce that they belong to Lita who was trying to hide her failure of playing the French horn for band.

As the primos solemnly rebury the mementos, Lita takes up the French horn again, having embraced her past mistakes.

Upon breaking up the incident, Buela reveals that Hacienda Hills' sister town, Fresadena, holds annual baby races, with the winner getting a lifetime supply of diapers.

They take a trip to Fresadena, where an ignorant woman misidentifies Bibi as Baby Bud's "nanny," inspiring her to join.

Her speech soon becomes moot as a minor earthquake carries Baby Bud across the finish line with the Ramirez-Humphrey family celebrating.

Inspired by the idea, the rest of the primos all proceed to hire segundos of their own, creating a very mish-mashed family.

These shorts primarily focus on Disney Channel characters meeting their various creators and learning how the concept of their shows were created.

[22] On June 15, 2022, at the 2022 Annecy International Animation Film Festival, it was announced that the show's first season would have an order of 30 episodes.

[23][24] In March 2023, Kline told Animation Magazine that the series was inspired by an adult short she had created for an Upright Citizen's Brigade stand-up comedy show in 2017, was inspired by Peanuts and Calvin and Hobbes, and said she loved working with the show's crew, praising their "intense passion, drive, and talent".

Some criticized the show's premise by drawing similarities to that of Nickelodeon's The Loud House and, more specifically, its spin-off series The Casagrandes.

[33][34][35] Other viewers criticized the opening sequence for presenting various negative stereotypes associated with Latin-American culture, argued the names of the setting and some characters could be considered offensive, and the Spanish grammar used was incorrect.

[36][37][38] Also criticized was the use of a "Mexican filter", a technique frequently used in American media to invoke a "foreign" atmosphere in Hispanic settings.

"[41] In an interview on June 16, 2023, Kline said the series is based on her personal experiences of growing up with a multicultural Mexican-American family in Los Angeles in the 1990s, being bicultural, biracial, and said that the project's relatability attracted well-known individuals like Melissa Villaseñor.

[4] The name of one of the characters was changed from Cookita to Lucita, as the former is similar to a vulgar term in several dialects of Latin American Spanish.

[43] As a result of online criticism, the series premiere was delayed several times, with reports this was done to make edits to already-completed episodes.

[44] Victoria Davis of Animation World Network interviewed Kline, who was glad to get feedback from the series, calling it an "amazing experience" to hear people's thoughts, saying it was "initially painful" but said that later responses honed her empathy, made her realize that the series could mean "so much to so many, in many different ways", and argued it gave her "strength to keep going.

Fernanda Camargo of Common Sense Media rated Primos 3 out of 5 stars, said the show depicts positive messages and role models such sharing and teamwork, and acknowledged the diverse representations among the characters, but noted the presence of stereotypes.

[46] Tony Betti of Laughing Place gave Primos a grade of 4 out of 5, praised the show for its humor and relatability, especially for those from large, multicultural families, complimented the diversity among the characters and said the series manages to be a distinct and entertaining addition to Disney TV Animation.

[47] The show has been nominated an Annie Award for "Best Animated Television/Broadcast Production for Children" in 2024 for the episode "Summer of Tater Luna".