World

World (世界, Sekai), also known as Human World or Earth is where humans reside.

Overview
The world is originally home to humans, devils which have been killed in Hell, fiends which are human corpses possessed by devils and hybrids which are humans with the ability to take the form of a devil. Prominent area of the world is Japan where Denji is living.

Japan
Japan is one the countries in the world and the main setting of the series. Its official language is Japanese. It is governed by a Prime Minister who had a contract with Makima. In exchange for working for Japan, any fatal damage inflicted on Makima is transferred to a random citizen of Japan. Public Safety Devil Hunters is working for the government of Japan.

In November 10, 1984 the Gun Devil hit Japan for 26 seconds killing 57,912 people. Aki Hayakawa witnessed the Gun Devil destroying his house and killing his family as it passed by.

In September 12, 1997 the Gun Devil appears again at the coast of Kaho City in Akita Prefecture for 12 seconds and killed several men, women and children. However, he is defeated by Makima and then he possessed the corpse of Aki. He is later defeated by Denji. After the defeat of Gun Devil, the Public Safety has formed Anti-Makima Squad to incapacitate Makima, however, they have been failed. Later, Denji defeated Makima by poisoning her blood and eating her piece by piece which allows him to bypass the contract of her and Prime Minister.

United States of America
The United States of America, shortly known as America is one of the countries in the world. Its official language is English. It is governed by a President who had a contract with Gun Devil. America also has twenty percent of the Gun Devil's body.

In November 10, 1984 a large terrorist attack involving guns occurred in America, causing that to be the day that the Gun Devil first appeared. The Gun Devil hit America for 124 seconds killing 548,012 people. Aldo, Joey and their brother survived the Gun Devil's attack but lost their home along with their father, mother and grandmother.

In September 12, 1997 President of the United States has been contacted with Gun Devil and applied their contract with Gun Devil to attack Makima by sacrifing one year from each citizen of the country.

Soviet Union
The Soviet Union, also known as USSR is one of the countries in the world. Its official language is Russian. It presumably governed by President of the Union. The Soviet Union have taken many children and placed in a special government program to make super-soldiers dedicated to the country. In this program children was subjected to harsh military training and scientific experiments to amplify her natural abilities. At some point a portion of the Bomb Devil's body was placed inside one of the children, thus turning her into a devil-human hybrid. The Soviet Union also has twenty-eight percent of the Gun Devil's body. The Soviet Union is the one which confirmed that the Gun Devil has been defeated by someone else.

In November 10, 1984 the Gun Devil hit the Soviet Union for 210 seconds killing 155,302 people.

Tolka and his master are also from the Soviet Union, the latter one is true identity of "Santa Claus".

China
China is one of the countries in the world. Its official language is Chinese. It is governed by General. China has eleven percent of the Gun Devil's body.

In November 10, 1984 the Gun Devil hit China for 32 seconds killing 316,932 people.

Quanxi, who is a hybrid and known as the First Devil Hunter, and her harem of fiends are also from China and work for the General.

After Makima has been defeated by Denji, the Control Devil has reincarnated in China as Nayuta which later found by Kishibe and brought to Japan to live in care of Denji.

Germany
Germany is one of the countries in the world. Its official language is German. Its governmental constitution details are unknown, however a government agent has been seen to hire a devil hunter. At some point of time, Nazi movement controlled Germany which led to World War II and the Holocaust. However, these have ceased to exist because of Chainsaw Man's ability to erase things from existence.

One of the perfect dolls of Santa Claus resides in Munich as a famed devil hunter with an alias of "Santa Claus of Germany".

Other Mentioned Countries

 * Canada - The Gun Devil hit there for 7 seconds killing 8,481 people.
 * India - The Gun Devil hit there for 15 seconds killing 29,950 people.
 * Mexico - The Gun Devil hit there for 2 seconds killing 6,088 people.
 * Hawaii - The Gun Devil hit there for 0.4 seconds killing 780 people.
 * Other countries besides America, Soviet Union and China have four percent of the Gun Devil's body. However, which countries has which percent of the body is unmentioned.

Trivia

 * In the panel where a street from USA is seen, there is a billboard of | Agni who is the titular protagonist of the | Fire Punch which is also created by Tatsuki Fujimoto.
 * In the world of Chainsaw man, followings are never happened or ceased to exist compared to real world: Nazi, World War II, dissolution of the Soviet Union, AIDS and nuclear weapons.
 * In the world of Chainsaw man, followings were existed on the contrary of real world but ceased to exist: Mount Hio eruption, Arnolone syndrome, SOA, the sixth sense, the light of particular star that would break children's mind, four other possible conclusions other than death at the end of living being' life spans and the name of human/devil hybrids.