The story begins with our protagonist named Kiro Suzuki Ishikawa, who was walking with his friend—a girl whose hair looked like a snowflake because of its white color and resemblance. They were talking peacefully until the girl suddenly ran off, and at that moment, a truck was about to hit her. Kiro pushed her out of the way just in time, but he took the full impact.
Then the scene shifts to Sone, who was running and accidentally fell off a mountain. Luckily, he survived. Sone wakes up on a hospital stretcher, but realizes something black is crawling into his mouth. In a desperate act, he grabs a syringe and injects it into his arm. Spikes appear in his hair. With a headbutt, he sends the black monster flying. Then, with a sonic-speed kick, he kills the black thing.
He opens the door and sees the lights are off—everything is very dark. He comes across a rift showing a universe. But what catches his attention is a syringe lying nearby. Ignoring the rift, he grabs the syringe. He sees a half-broken window and, with a quick throw, launches the syringe through the broken part of the window. The syringe injects itself into the arm of Worh, the third protagonist.
The black thing was crawling into him too, but Worh slaps it away because the syringe woke him up, allowing him to kill the black entity. With one punch, he destroys the wall. Meanwhile, as Sone is running, he finds another syringe in a different rift that looks like a universe. He throws that syringe through another window, breaking it. The syringe injects into Kiro's neck, who was awake. He feels his emotions changing. He kills the black thing and a brown one that were watching him.
The three protagonists—Sone, Worh, and Kiro—meet. They hear a scream and immediately rush toward it at hyperspeed. They find a little girl and a boy trapped in a cage in a large place. At that moment, Boss 1 appears and says, "Who are you, and why are you defying the laws of this damn place?"
He quickly throws a punch, which the protagonists dodge. With a single strike, Kiro kills Boss 1. They free the girl and the boy from the cage. The girl returns home with her parents after the protagonists escort her back. The boy stays with them, but they notice his teeth are sharp.
The boy says, "I can chew metal with my teeth and eat all kinds of meat—even human flesh."