Production spanned approximately seven years, facing delays as it navigated challenges related to the COVID-19 pandemic and Miyazaki's slowed animation pace, before nearing completion in October 2022. Financing for the project involved streaming deals for previous Ghibli films.

Mahito's father Shoichi, an air munitions factory owner, marries his late wife's sister, Natsuko, and they evacuate to her rural estate.

Leading one of the estate's elderly maids, Kiriko, into the tower, Mahito is deceived by a watery imitation of his mother made by the heron, which dissolves at his touch.

The wizard, preoccupied with a stack of stone toy blocks representing their dimension, requests Mahito, possessing the power of his bloodline, to succeed in the custodianship of this world.

[11] After Suzuki publicly announced the start of work on Miyazaki's new film in February 2017,[12] the studio's official website posted a call for staff for the new project on May 19, 2017, and production began in earnest.

[14] At an event held at Waseda University in October 2017, Studio Ghibli announced the film would be titled Kimitachi wa Dō Ikiru ka, after the 1937 novel by Genzaburō Yoshino.

Miyazaki did not use a computer or smartphone and was unaware of online streaming, so Suzuki convinced him to make this deal to cover the costs, especially considering that the project differed from their previous endeavours.

[23] Cinematographer Atsushi Okui introduced the idea of utilizing Dolby Cinema to Miyazaki during the production of Earwig and the Witch, which received the director's approval.

[24][25] In October 2021, the director conveyed to T that he was making the film because he did not have an answer to the question Kimitachi wa Dō Ikiru ka, while the producer characterized the forthcoming release as an ambitious fantasy project.

[33] The English cast, unveiled on October 17, features Christian Bale, Dave Bautista, Gemma Chan, Willem Dafoe, Karen Fukuhara, Mark Hamill, Robert Pattinson and Florence Pugh.

[35] The hospital fire at the beginning of the film evokes personal parallels with Miyazaki's loss of his mother,[36] who was known for her strong opinions and is believed to have been a source of inspiration for several of the director's female characters.

The narrative is inspired by Miyazaki's (Mahito) professional relationships with Isao Takahata (Granduncle) and Suzuki (Heron), and integrates themes of destruction, reconstruction and imagination.

He also mentioned a meeting he had attended at Studio Ghibli's offices in 2017, during which Miyazaki articulated his intention to create the film and reminisced about his past works, primarily featuring cheerful and optimistic male protagonists, and contrasted them with his perception of boys as complex individuals.

Yoshino drew a distinction between The Boy and the Heron and Kimitachi wa Dō Ikiru ka as separate works, yet highlighted their shared central theme—how individuals navigate and come to terms with a world characterized by strife and loss.

The film, open to diverse interpretations, fundamentally conveys resilience in the face of conflict and grief, while advocating for the cultivation of meaningful friendships and trustworthy alliances, ultimately promoting progress and fostering "humanity and understanding to the world.

It draws attention to the film's departure from the conventional children's genre, instead aligning more closely with the "violent" style of Princess Mononoke rather than the "cuddly charm" of My Neighbor Totoro, with the exception of the Warawara characters.

[40] As highlighted by Unseen Japan, the film's themes make the viewer reflect on their role in a world marked by violence and uncertainty, their obligations to future generations and their connection to their ancestors.

[41] This view is shared by some publications, commenting that Miyazaki's recurring exploration of mortality and the aftermath of profound loss is a central theme in the film, showing the importance of everyday choices and depicting a journey of self-discovery and the search for meaning amidst the uncertainties of life,[42][43] and underlining the film's open-ended approach, in contrast to the book, which is centered on the moral development of adolescent boys.

The narrative imparts various moral lessons but centers on an "impassioned plea" from an aging master (Granduncle) to his descendants, emphasizing the urgency of their tasks as time passes quickly.

Suzuki witnessed Miyazaki singing the song with children at Ghibli's nursery school, and the director approved the composition after reviewing a demo recording.

Yonezu, shown storyboards and provided with project details, engaged in a five-year creative process with Miyazaki and Suzuki, resulting in the completion of the musical composition.

The decision to do so came from Suzuki, who opted to eschew traditional marketing methods due to concerns about over-revealing film content, in response to what he believed to be a fundamental preference among moviegoers for a more enigmatic cinematic experience.

[59] After the preview screening held in late February 2023, where strict confidentiality measures were in place, a message from Miyazaki was read out following the end credits, saying, "Perhaps you didn't understand it.

The achievement has evoked mixed feelings among industry insiders, with distribution representatives expressing concerns to Ōtaka, fearing the challenge of this no-promotion strategy on their livelihoods and the necessity of traditional advertising methods.

The site's critics consensus reads: "Soulfully exploring thought-provoking themes through a beautifully animated lens, The Boy and the Heron is another Miyazaki masterpiece.

[131] Similarly, Time Out Japan hailed the film as "a mature, complex masterpiece, weaving together the director's past, present, and future – a beautiful enigma that promises to be worth the wait.

He stated that there is a nostalgic longing for the past that evokes the impression of a director reflecting on their career before stepping away, and this underlines "the makings of a perfect swan song".

[132] In his review for The Japan Times, Matt Schley awarded the film a rating of 4.5 out of 5 stars, expressing that while its position within his list of favorite Miyazaki works remains uncertain, there were moments that left him breathless.

[37] While acknowledging the film's complexity and potential to not resonate with all viewers, Full Frontal author Matteo Watzky regarded these qualities as its best aspects, showcasing Miyazaki's talent, subtlety, and imagination.

[133] Caryn James of the BBC, who rated it 5 out of 5 stars, felt the film is the culmination of Miyazaki's career and therefore may require multiple viewings to fully absorb the narrative's unwavering pace and the rich tapestry of imagery.