Season 1

Yuya Nomoto, an ordinary college student, met a mysterious high-school student called Hitomi after being involved in an incident, and saw her transform into a beast and fight a Leo monster at a landfill. They're Therianthropes who have brains of humans and fangs of beasts. Hitomi is Ratel, a Brute with the strongest killer instinct. Nomoto gets involved in their battles called Killing Bites.

Nomoto, whom became the player for Ratel, got attacked that night by Rowdy. Rowdy tries to get information about Ratel from Nomoto, but Hitomi appeared, and it turned into a battle between Ratel and Rowdy. Nomoto is also targeted by Rowdy during that battle, but then, Okajima, the Giant, appeared. And Okajima, whom saved Nomoto, asks Hitomi to do him a favor.

Hitomi learns about Killing Bites Destroyal (a battle between the top four zaibatsu) after a cat fight with Eruza Nakanishi. Hitomi decides to enter the game as Ishida zaibatsu with Okajima, but the Destroyal is a team battle for teams of three. They need one more member, but they have difficulty finding that person. Meanwhile, Okajima gets in touch with Ui Inaba, who's a Therianthrope of Rabbit.

Hitomi and Nomoto were at a party on a luxury ship which was on its way to the arena. On the ship, each side's elites were ready for a fight, including the previous winner, Taiga Nakanishi, a Therianthrope of Tiger. Before long, they arrived at the stage of the game, the Hotei island (a remote island). On the contrary to the other player's expectations, Nomoto went for an outrageous strategy.

While the battle between Ratel and Bear was ongoing, Ishida camp's Hippopotamus, Sumitomo camp's Crocodile, and Mitsukado camp's Gorilla were facing Yatsubishi camp's Tiger at a different site. Unintendedly, the three forces joined forces to challenge the previous winner. In spite of the odds, Tiger was showing off his strong power.

Cheetah was in a tight spot because she was being attacked by Cobra and Gecko, but was saved by her rival, Ratel. They forge a coalition, but they experience a hard battle. On the other hand, it seemed like a clear victory for Tiger in the battle between him and the other three forces, but he was now in a tight spot due to the Sumitomo campâ€TMs plot. Then, Hippopotamus did something unexpected.

After Tiger left, a battle between Crocodile and Hippopotamus was taking place. Mitsukado camp's Kido and the once defeated Yabe, a Therianthrope of Gorilla appears. Crocodile, who got his game cut short bare his fangs towards Kido. While that was going on, the battle between Cobra, Cheetah, and the team of Ratel and Gecko was getting especially intense.

Zaibatsu chairman, Mitsukado, and the other leaders of the top four zaibatsu were watching the game in the VIP room on the ship. The Destroyal was also a proxy war between the zaibatsu to decide who'd get the decision-making power for the theriomorphosis business which is likely to yield huge profits. On the island, Ratel and Cheetah were in an unthinkable state because of Civet's Civetone Trap.

Finally, the battle between Tiger and Ratel has begun. Ratel still rose up after Tiger's killer move, Kohou, but the difference in their power was clear. Ratel was gradually being driven into a corner while Tiger showed off his strong power. Nomoto, who was watching that on the ship, was conflicting whether to let Ratel escape or not. And finally, Nomoto makes his decision.

Pangolin, the ultimate weapon of the Mitsukado zaibatsu, burst into Ratel and Tiger's battle and dismisses Ratel in one blow. Even Tiger's claw attacks have no effect on Pangolin's scales which can act both as offense and defense. Shidoh (Director General of Killing Bites), who was watching the battle in the monitor room, was remembering when he met Hitomi before becoming a Therianthrope.

The climactic battle between Ratel and Pangolin, who came back as a Origin Beast was becoming especially intense. Pangolin overwhelms Ratel with his outrageous power, but Ratel was actually enjoying the battle against this powerful enemy. While the battle was getting heated, a disgusting memory was coming back to Pangolin's mind. Finally, the two sexes of the Destroyal will fight!

The Destroyal finally came to an end. However, the live feed got cut off immediately. It was because of a scheme to invalidate the Destroyal by killing all the Therianthropes and crew. The evil clutches approaches Hitomi and the others whom fought through the games. And the political war over theriomorphosis surgeries that used Killing Bites as a proxy war developed rapidly, and a new age begins.