TOKYO — Distrib Toho and its partners have decided to advance screen the last pic of the smash hit “20th Century Boys” sci-fi action trilogy minus its ending.

Starting from late July, Toho will hold press screenings of the final part of the Yukihiko Tsutsumi dystopian epic — the title of which translates as “20th Century Boys — The Last Chapter: Our Flag” — minus its last 10 minutes.

The idea is to prevent leaks about the true identity of a mysterious cult leader, called only “Friend” (Tomodachi), who seeks to realize the dire “prophecies” a gang of boys dreamed up back in 1969. The main author of the “prophecies,” grown to become a convenience store manager (Toshiaki Karasawa), joins with his old pals in 1997 to stop the cult and unmask its leader. The story concludes in 2017.

The ending of the trilogy was a top secret while the pic was in production, with scripts doled out only on a need-to-know basis and only 10 people in total knowing how the pic truly concludes following various edits and revisions in post.

The first part of the trilogy, based on Naoki Urasawa’s best-selling comic and produced by the NTV network and its partners, earned $40 million following its August 2008 release, while the second part, which bowed in January, scored $30 million. The third and final part is expected to greatly exceed those numbers.