- The film is inspired by the 1937 novel of the same name by Genzaburo Yoshino, but has an original story that is not a direct adaptation of the novel.
- It will be Hayao Miyazaki’s final film and is intended to be his parting gift to his grandson.
- The film was released without any traditional marketing campaign, with no trailers nor promotional stills of the film released before its premiere with the exception of a single poster.
- Hayao Miyazaki started working on the film in 2016 without receiving an official green light.
- In a late 2019 interview with NHK, Miyazaki stated that the film is not to be expected anytime soon; he said that in his younger age, he used to produce 10 minutes of animation every month, but now his speed was reduced to 1 minute per month.
- Hayao Miyazaki originally hoped to finish and release the film in the summer of 2020 to coincide with the Summer Olympics in Tokyo, Japan; which were eventually postponed until 2021 due to the COVID-19 pandemic.
- The Boy and the Heron was theatrically released in Japan on July 14, 2023, by Toho, and was screened in both traditional theaters and other premium formats such as IMAX.
- In Japan, The Boy and the Heron grossed $13.2 million (1.83 billion yen) in its opening weekend, becoming the biggest opening in Studio Ghibli’s history and surpassing Howl’s Moving Castle’s 1.48 billion yen debut in 2004. The film earned $1.7 million from 44 IMAX screens, setting a new 3-day record.