Celebrating the 20th anniversary of the Tokusou Sentai Dekaranger series, the six detectives who fight with cool and burning hearts gather again to face the "Great Plan" that threatens peace on Earth!

The Dekarangers must deal with a mysterious undercover agent from another planet while trying to save her world and Earth from one of the universe's toughest Alienizer gangs.

When a powerful new Makamou attacks and defeats Hibiki, Asumu dives into Takeshi’s history and discovers a book that details the ancient Oni and a boy sharing his name. As he reads on, he learns of the tensions between humans and Oni as they struggle to stop the Orochi Makamou, but will he discover the key to defeating the new Orochi in the present?

A mysterious international crime organization makes a demand of 900 million yen from the Japanese government for the release of hostages. The group then targets a victory parade of a world sports game to commit indiscriminate terror.