The Yakumo Cabinet Policy, or Yakumo (八雲, eight clouds) for short, is a document in killer7 that outlines the foreign policy of the United Nations Party, whose stated purpose is to unite all the countries of the world under Japanese rule. It was originally drafted by the Union 7 in 1953. The Yakumo's instructions are extremely potent, and anybody who uses them can garner immense political power. Whether the Yakumo harbors actual supernatural powers is ambiguous, but it is said to have to have the power to change the world and control human nature. If it is a supernatural document, the source of its abilities may be Kun Lan.
After being written by the Union 7, the Yakumo was passed to the the chief secretary of the Liberal Party; shortly thereafter, the Union 7 and other defectors (presumably including the chief secretary, or whoever they passed the Yakumo to) joined the United Nations Party and used the Yakumo to overtake the Liberals in Japan's political arena. By the time the game takes place, Union 7 and UN Party member Toru Fukushima had hidden the Yakumo somewhere in his restaurant.
In 1996, a postal worker named Andrei Ulmeyda accidentally found a copy of a piece of the Yakumo in the postal system. He started up a business, First Life, Inc., and, almost solely using the Yakumo, took over the entire town in the span of a few months, renaming it after himself.
In Sunset, the Liberal Party dispatches Japanese assassin Julia Kisugi to retrieve the Yakumo from Fukushima. Following the fighting at the party ancient's restaurant, Kisugi murders Fukushima but is left empty handed as Jean DePaul, another assassin in the employ of the International Ethics Committee, had already obtained and smuggled out the Yakumo. Following DePaul's own death at the hands of the killer7, its whereabouts is unknown, though according to DePaul, now a Remnant Psyche, Kenjiro Matsuoka, the leader of the UN Party following Fukushima's death, had got his hands on it. The Smiths also later kill Ulmeyda at his request; Gabriel Clemence inherited Ulmeyda's Yakumo.
In 2020, part of the Yakumo was made public. It became the subject of devout worship.
The word "yakumo" has significance in the history of Japanese writings, as it appears as the first word in the oldest recorded Japanese poem. The poem appears in the religious text the Kojiki, which is also the oldest written work in Japanese literature. In the Kojiki, the poem in question is created by the kami/god Sasunoo.
"Yakumo" as a name is also significant to the history of Japan-US relations, as part of the Japanese name Koizumi Yakumo adopted by writer Lafcadio Hearn, who wrote several books about Japan after he moved there in the 1890s; Yakumo's books gave many people in the west their first exposure to information about Japan.
- A document called the Yakumo Manifest is also mentioned as predicting some of the events of Short Peace: Ranko Tsukigime's Longest Day. It is unknown if these are meant to be the same document, but the overall theme of the Short Peace project is "Japan", meaning they very well may represent similar things.