Photo/Illutration Nagate, the protagonist of "Knights of Sidonia: Love Woven in the Stars" (Provided by Klockworx Co.)

The popular "Knights of Sidonia" CGI anime series will culminate in a feature film adaptation that shows humankind locked in a fateful final battle against a mysterious alien species called the Gauna.

"Knights of Sidonia: Love Woven in the Stars" is scheduled to hit cinemas on June 4.

The film weaves together the grandiose final battle and the protagonist's love story, along with yet to be resolved matters from the past.

"I wanted to tell an ensemble story in which many feelings develop into a large vortex," said director Tadahiro "Tady" Yoshihira.

The space opera series is based on a science fiction manga of the same name by Tsutomu Nihei.

The story is set in a dark future and follows what may be the last of the human race as it travels in a massive spaceship called Sidonia.

The protagonist, Nagate, is an ace pilot of the Garde, a human-shaped mechanized robotic weapon.

The film closes in on the secret of Nagate's birth and the captain's past and other secretive mask-wearing officials on Sidonia who have sent young pilots into battle.

"The three main elements of the story--the love story, the cursed past and the final battle--generate a chemical change before it lands in the future in the end," Yoshihira said. “I felt tremendous pressure to finish it properly, as I was entrusted to do the final part of the saga.”

"Knights of Sidonia" aired for two seasons, starting in 2014.

Although Yoshihira initially worked on it as an editor, he became interested in directing when he was asked for his opinions by the director at the time. He became the sub-director for the second season before he insisted on serving as director for the film adaptation.

Yoshihira made his directorial debut with "Drifting Dragons," a CGI anime series that aired on TV last year that was also adapted from a manga comic. The facial expressions and acting by the characters in that show were intentionally rendered to look softer than normal CGI animation to give it a more manga-like style.

"The CGI models for 'Sidonia' have been improved to give them a greater range of emotional expressions," Yoshihira said. "'Dragons' is a story about misfits going wild in a world set in the 19th century. 'Sidonia' is a sci-fi story taking place in a future world 1,000 years from now full of lifeless artificial objects, so the visuals were made to look solid on purpose. I think that's the difference."