A young boy uses his scientific skills to fight enemies.

Duke Fleed is a survivor of the Fleed Planet who is escaped to the Earth, onboard a mysterious "spaceship", where is raised by Dr. Umon as his adoptive son, and known as Daisuke Umon. Years after his arrival, he's faced with the threat of King Vega and his army, who want to conquer the Earth. With his friends Koji and Hikaru (and later his younger sister Maria Grace), Duke decides to fight back using his best weapon - the almighty Grendizer.

In the Kingdom of Yamauchi, people have the ability to transform into three-legged crows known as yatagarasu. While the men plot over daily governance, women compete for the hand of Wakamiya, the crown prince who was selected as the Kinu, the servant to the Mountain God. Four young women arrive at the court to join the competition, including one named Asebi. While the kind and innocent Asebi sticks out like a sore thumb compared to the other women, the crown prince has to fight for his place in the clan. Despite being born both to a concubine and as a second son, the royal priests still chose Wakamiya to be the Kinu over his older brother. This decision created a rift between the siblings while enraging Wakamiya's stepmother in the process. When Yukiya, one of the teenage sons of the village chief, is sent to the palace to become Wakamiya's new attendant, the prince is not pleased in the slightest. However, Yukiya's presence at the imperial courts is no mere coincidence.

In a world of anthropomorphic animals, Belle Lablac was born as the only human being. Having no fangs, fur, or scales, she was called "Faceless," and she lived a lonely life with no one else she could identify with. "I want to be part of the world..." With such longing in her heart, she decides to set out on a journey to find her roots, carrying the Runding, a great sword as tall as she is. She doesn't know how many adversities await her along the way...