10 Movies Teased In Other Movies YEARS Earlier

And finally, we end with a devastating monument to unrealised promise, with the late, great Satoshi Kon's masterful 2006 animated sci-fi thriller Paprika.

At the end of the film, Konakawa (Akio Ōtsuka) visits the movie theatre, and amid the posters of films showing are several of Kon's prior works, namely Perfect Blue, Millennium Actress, and Tokyo Godfathers.

But there's one poster that stands out among the bunch - "Dreaming Kids," which Konakawa ends up buying a ticket for. Dreaming Kids was a reference to Kon's planned next feature which was eventually entitled "Dreaming Machine."

Sadly Kon died in 2010 with only 40% of the film's shots completed. The production team continued to work until funding ran out, after which it was heartbreakingly shelved.

Though Dreaming Machine is currently considered cancelled, there are still periodic discussions about reviving it with another director, such that Kon's final vision, albeit unavoidably compromised, can one day be seen by his fans.

As Dreaming Machine wasn't ever released, this tease takes on an altogether more melancholic, poignant meaning, a hint at what could have been, and perhaps one day still might be.