Dead Mount Death Play

In a distant world, Shagurua, the hero known as the Calamity Crusher, battles a necromancer without peer known as the Corpse God in order to save the world. After a fierce battle, just when Shagurua appears to have defeated the Corpse God, a magic is activated, surrounding the area with light. At that moment, the soul of the Corpse God is transferred to a faraway world, and he wakes up in modern Shinjuku in the body of a young boy, Polka Shinoyama, who had just been murdered. As he wanders around town in the body of Polka, he is rescued by a girl who calls herself Misaki Sakimiya. Upon seeing her, Polka's memories gradually return.

Polka tries to get his bearings while fighting his would-be killer's colleagues.

Living in a torture building, Polka seeks a peaceful life along with his new friends, Takumi Kuruya and Misaki Sakimiya. A man appears, wanting to hire an assassin-killer Misaki. He makes the request for her to assassinate the henchman of an assassin she killed in the past, unaware that it is a trap. Meanwhile, the investigators of Materials Compiling Group #3 of the Shinjuku Police's Community Safety Division, commonly known as Comps-3, spring into action.

Materials Compiling Group #3 of the Shinjuku Police's Community Safety Division, commonly known as Comps-3, is tasked with dealing with mysterious crimes which cannot be made public or wouldn't be believed even if they were. Chief Tsubaki Iwanome and his men, who refer to such criminals as troublemakers, continue to pursue such unsolved mysteries. Comps-3 is now tasked with investigating the incident caused by Polka - the bones that were found at the scene of the fire as well as the men who were found tightly bound. Kouzaburou Arase of Comps-3 meets Polka and Misaki and senses that Misaki is involved in the case. Meanwhile, Iwanome is suspicious of Clarissa and questions her heavily at the bar, Youtoukorou, where Polka and Misaki appear.

In the darkness, Polka and the others confront Lemmings. Lemmings is about to take Misaki away, but Polka isn’t able to act quickly for the fear of having Iwanome and his men see him using magic while also not wanting to sacrifice peace by fighting Lemmings. Polka realizes that he needs power to gain peace and decides to begin working as a fortune-teller with the help of a mechanical pencil, which he imbued with the spirit of Hosorogi, who died five years ago. As Polka steadily makes profits as a fortune-teller with the help of Takumi and Hosorogi, Kazuki and Shizuki Shinoyama, his twin sister and brother visit Polka.

Along with Misaki, Polka visits the Shinoyama family, meeting Takeru Shinoyama and other members of the family. Rozan Shinoyama, Polka's father, detects that Polka is not the real Polka and interrogates him, but hurries to rescue Kazuki and Shizuki upon sensing that they are in danger. Having also assassinated Suzuka, the twins' older sister, Fire-breathing Bug is now after the twins under the command of Goro, their relative.