Gatchaman

In 2066, the Republic of Hontworl abruptly withdraws from the United Nations, unsettling an already fragile world. Soon afterward, the capital of Triad is attacked by the enormous bird-like fortress Turtle King, and leading scientists connected to the International Science Organization begin disappearing.

Dr. Kouzaburou Nanbu calls the Science Ninja Team back into action. Ken the Eagle and his four teammates once fought the Galactor organization, but the new threat is powerful enough to place global security in danger once again. To stop it, the five Gatchaman warriors must uncover who is behind the attacks before the enemy's strange technology overwhelms them.