Batkid

Batkid Begins is a 2015 American documentary film co-produced, co-written and directed by Dana Nachman. The documentary follows Miles Scott, an American child and cancer survivor. His wish was to be "Batkid", a sidekick of the eponymous comic book superhero Batman. Once the request went out, thousands of volunteers, city officials, businesses and supporters rallied to turn San Francisco, California into "Gotham City" – the fictional home city of Batman, on November 15, 2013, for one of the largest and most elaborate Make-A-Wish projects ever staged.

Synopsis from Wikipedia, CC BY-SA 4.0. Everything below written here.

Poster © the film's rights holders.