TV-Series
Description
Kashin is a central antagonist and the primary ruler of the subterranean world known as the Underground. He holds the title of founder and absolute leader of the Company, the powerful organization that governs the secret city beneath Tokyo. Kashin was not originally a tyrant; he was once regarded as a hero of the Underground. In the chaotic early days of that world, he fought alongside four other individuals named Shūjin, Seki, Tail, and Chelsea to establish order, ultimately building the very society he later comes to control.

In his role as the story's final boss, Kashin's personality is defined by its ruthless and merciless nature. He is the architect of the Company's oppressive regime, which exiles anyone who rebels against its authority to the lowest and most miserable levels of the Underground, known as the slums. His motivations are deeply personal and vengeful, rooted in a desire for revenge against the surface world. However, his primary driving goal is the resurrection of a person named Sarasa. His plan involves recovering a dragon and, more crucially, using a clone named Ruri Sarasa. He intends to transfer the memories of Sarasa into Ruri, effectively bringing the original person back to life. This explains why the Company relentlessly pursues Ruri after she escapes to the surface.

Kashin's relationships are defined by his power and his singular goal. He is served by the Company and its elite warriors, known as Sūpei, who carry out his orders. He was once a comrade-in-arms to characters like Chelsea, but her decision to help Ruri escape to the surface brands her a traitor in his eyes, and he becomes one of her primary adversaries. His former companion Seki is also one of the powerful fighters who works for the Company to recapture Ruri. Throughout the story, Kashin operates from the shadows, directing the efforts to recapture Ruri and eliminate the protagonists who interfere with his plans. He is first mentioned as a mysterious and powerful figure, making his full appearance as the ultimate threat the heroes must overcome. His development is presented as a fall from grace, transforming from a celebrated hero who built a civilization into a villain willing to sacrifice the present for the sake of a past he cannot let go of.

Kashin possesses notable abilities that set him apart from other elemental users in the Underground. While most characters manipulate a specific element such as fire, water, or gravity, Kashin's powers are not bound to a single element. He has the formidable ability to nullify all elemental attributes, effectively canceling the attacks of his opponents. In addition to this nullification power, he wields a sword with which he can cut through anything. These two distinct abilities, described as void and slash, make him an extraordinarily dangerous and nearly unstoppable combatant. He stands approximately 176 centimeters tall and has AB blood type.
Cast