"Ultra B: Dictator B.B. from the Black Hole" is a science fiction anime series set in a distant future where humanity faces an existential threat from an alien dictator. The story begins with the sudden appearance of Dictator B.B., a ruthless ruler from a black hole, who seeks to conquer the universe. His advanced technology and overwhelming military force quickly subjugate multiple planets, including Earth. The narrative centers on the resistance efforts led by a group of young pilots who operate advanced mecha units known as Ultra Bs, designed to combat B.B.'s forces.

The protagonist, Ken Kurenai, is a skilled pilot and the leader of the resistance. Alongside his teammates, including the tactical genius Aoi Ichijou and the hot-headed but loyal Ryu Suzaki, Ken pilots the flagship Ultra B unit, which becomes humanity's last hope. The series explores their struggles against B.B.'s relentless attacks, as well as the personal growth and camaraderie among the team members. Key plot points include the discovery of B.B.'s origins, the development of new Ultra B technologies, and the moral dilemmas faced by the resistance as they fight to protect their world.

Throughout the series, the narrative delves into themes of sacrifice, unity, and the resilience of the human spirit. The resistance faces numerous setbacks, including internal conflicts and the loss of allies, but they remain determined to thwart B.B.'s plans. The climax involves a final confrontation between Ken and B.B., where the fate of the universe hangs in the balance. The series concludes with a resolution that ties together the central conflicts while leaving room for reflection on the cost of victory and the enduring spirit of resistance.