On November 20, 2024, Seven Seas Entertainment announced that they had acquired the license to publish a new translation of the series in English, with the first volume scheduled for release in July 2025.

The series was licensed and distributed by Media Blasters in the United States at the time of its initial Japanese broadcast.

Yoko Nakajima, an unhappy high school student, is one day suddenly faced with a strange man who swears allegiance to her.

Their status as "Kaikyaku" (people who come from Earth) makes them hunted fugitives, so they wander the land of the 12 countries, simply trying to survive and figure out the reason they were brought to this world.

It is located on a group of several islands in another dimension accessible from our world through portals created from naturally-occurring magic (though the other way around is normally impossible).

Eight of the Twelve Kingdoms (Kei, En, Ryu, Kyou, Han, Sai, Sou, and Kou) border at least one of these four seas, extending from the center like the petals of a flower.

One short story, Drifting Ship (漂舶, Hyouhaku), published in 1997, accompanied the drama CD for Higashi no Wadatsumi, Nishi no Sōkai[8] and remains uncollected elsewhere.

In February 2008, the new Twelve Kingdoms short story, Hisho no Tori (丕緒の鳥) was published in Shinchosha's Yomyom magazine, followed by Rakushou no Goku (落照の獄) in September 2009.

In 2024, Seven Seas Entertainment announced that they had acquired the license to publish the novels with a new translation under their “Airship” imprint.

[12] The anime adaptation by studio Pierrot aired from April 9, 2002, to August 30, 2003, in Japan on NHK for forty-five episodes.

The anime series has been released on DVD and Blu-ray in the United States by Media Blasters, which are now out of print.

Konami has released in Japan two games based on Twelve Kingdoms, both produced by Takashi Shimomichi.

Juuni Kokuki: Kakukakutaru Oudou Kouryoku no Uka was released for PlayStation 2 on April 4, 2004, and is a sequel to the first game, continuing with Yoko's problems after she becomes the monarch of Kei.