"Time Bokan: Gyakushū no San-Okunin" is a 2017 anime series that serves as a sequel to the 2015 reboot of the classic "Time Bokan" franchise. The story revolves around a group of adventurers who travel through time to uncover the truth behind a mysterious treasure known as the "Golden Condor." The series is set in a world where time travel is possible, and the protagonists use a time machine called the "Time Bokan" to explore various historical periods and alternate realities.

The main characters include Maruo, a young and enthusiastic inventor; Tokio, a skilled pilot and Maruo's childhood friend; and Kanna, a strong-willed and resourceful girl who joins their team. Together, they form the "Time Bokan Crew," dedicated to finding the Golden Condor and protecting it from falling into the wrong hands. Their primary adversaries are the "Dokurobey Gang," a trio of villains consisting of the cunning leader, the strong but dim-witted enforcer, and the eccentric inventor. The Dokurobey Gang seeks the Golden Condor for their own nefarious purposes, leading to frequent clashes with the Time Bokan Crew.

Each episode typically follows a formulaic structure, with the Time Bokan Crew traveling to a specific time period or alternate world, encountering historical figures or fantastical elements, and engaging in battles with the Dokurobey Gang. The series incorporates humor, action, and historical references, often blending real-world history with imaginative twists. The Golden Condor serves as a recurring motif, with its true nature and significance gradually revealed over the course of the series.

The narrative explores themes of friendship, perseverance, and the consequences of tampering with history. The characters' interactions and growth are central to the story, as they learn to work together and overcome challenges. The series also pays homage to the original "Time Bokan" franchise, incorporating familiar elements and characters while introducing new concepts and settings. The episodic nature of the show allows for a variety of adventures, each contributing to the overarching quest for the Golden Condor and the ultimate resolution of the conflict between the Time Bokan Crew and the Dokurobey Gang.