In 2007, referring to the character's appearances in Summer Heights High, Sydney Morning Herald television critic Michael Idato wrote that "Jonah Takalua is well on the way to becoming the voice of his generation.

[3] In order to develop the character's voice and mannerisms, he met and interviewed Pacific Islander children and "just naughty teenage boys", studying their behaviour and speech patterns.

[4] As a white man in his late thirties, Lilley knew he could not easily pass for a Tongan teenager, and so deliberately surrounded Jonah with other Pacific Islander boys in order to make him more believable.

In the final episode of the Summer Heights High, Jonah is revealed to have been expelled, and is stated to be returning to his native Tonga to live with his uncle.

On the final day of term, Jonah performs his story in front of the Gumnut Cottage audience, revealing a sensitive and heartfelt statement which epitomises the difficulty faced by the character, due to the racial and cultural barriers satirised within the program.

The series was called "racist",[5][6][7][8] and "dreadful"[9] and spawned an online protest movement by young Tongans concerned at how Lilley's inaccurate portrayal might affect their communities and futures.

[10] Prachi Gupta wrote in Salon: "While this show is a greater disservice to Tongans in Australia, this type of caricature is just as harmful in America, where our only mainstream knowledge about the Polynesian culture now consists of Lilley’s character.

It’s disappointing that HBO, a network that is often considered the gold standard of television (and one that is trying to improve its record on diversity), will air "Jonah From Tonga" tonight.

[11] Lilley's portrayal of Jonah in Summer Heights High was broadly well received by critics, with many praising the 33-year-old's ability to embody the teenaged character so convincingly.

"[12] Catherine Deveny of The Age described Lilley's performance as "perfect",[13] while Karla Peterson of The San Diego Union-Tribune praised him as bringing to the role a "cherry-bomb energy and an outsider's empathy that makes Jonah such an aggravating charmer".

[15][16] His struggles with racism, an unstable home life, and a school unable to understand his needs form the most heartbreaking aspect of the series, said Dean Flannery of CBC News.

Dave Shiflett of Bloomberg found him the "most annoying" of Lilley's three characters, although he added that his sympathy for Jonah increased as the series progressed.

[21] In September 2007, the Herald Sun raised concerns about the impact of the show on students, with parents and teachers reporting that children were adopting Jonah's habit of referring to others as "homos" and telling adults to "puck off".

[22] However, youth researcher Professor Johanna Wyn dismissed these concerns, arguing that young people are now much more sophisticated in the way in which they consume media and would not see the show as a model for behaviour.