Planet Ladder (プラネット·ラダー Puranetto Radā?) is a fantasy science-fiction shōjo manga written and illustrated by Yuri Narushima. Appearing as a serial in the Japanese manga magazine Crimson from March 1998 to May 2003, the chapters of Planet Ladder were published by Sobisha/Shueisha in seven tankōbon volumes from December 1998 to May 2004. Based on the Japanese folktale The Tale of the Bamboo Cutter in which a young girl named Kaguya-Hime is discovered to be the princess of the moon, the story focuses on a teenager named Kaguya, who is prophesied to save only one of the nine parallel worlds, and her quest to bring peace to a waring universe while finding her true identity.
Planet Ladder was licensed in North America by Tokyopop and released from April 2002 to March 2005 after being serialized in Tokyopop's manga anthology Smile. Planet Ladder was part of Tokyopop's line-up of manga in its original right-to-left format; previously, the majority of manga licensed in the United States was "flopped" to read left-to-right for a Western audience. Sales of Planet Ladder were positive with two volumes ranking in the best-selling graphic novel list and the series received positive reviews from English-language critics. On April 2, 2007, it went out of print in North America.
The series focuses on Kaguya Haruyama, a four-year-old amnesiac girl found abandoned on present-day Earth. For years she lives with a Japanese foster family until two men—Idou, a monk, and Seeu, an emotionless prince—appear in her home one night and fight over her. Gold, Seeu's robot modeled after Kaguya's deceased brother Kagami, brings her to a world parallel to Earth on Seeu's orders. After exploring the world with Gold, she encounters Shiina Mol Bamvivrie who believes Kaguya is the "Girl of Ananai", destined to save only one of the nine parallel worlds from collision. Shiina explains that nine worlds exist: Ancient, the first civilized world that was mysteriously destroyed; Asu, Seeu's disintegrated world; Eden, present-day Earth; Telene, a small world allied with Geo; Fifth World, a politically neutral world; Geus, a peaceful world under the control of Geo; Geo, the most powerful of the worlds; Asuraitsu, Geo's rival; and the Ninth World, destroyed before the start of the series.
Shiina and Waseda, a Tokyo University student trapped in the body of a giant rooster, join her and Gold in traveling across Telene. After learning that Seeu watched his people die from an incurable virus spread around Asu, Kaguya decides to change the fate of the worlds by confronting Kura, Geo's indulgent emperor who ordered her kidnapping. Instead, while en route to Geo, Gold brings her to Seeu's floating castle in Asu and Kura captures and recruits Shiina into his army.
Kaguya later makes an interplanetary broadcast, announcing her refusal to save only one world. Instead, she plans to find a person to help her save most of the worlds and people. Kura begins to destroy other worlds to increase Geo's survival chances. Deciding to use Kaguya as a political figurehead, Kura sends Shiina to abduct her; once there, Kaguya refuses to help him. Angered, Kura divulges that the "Girl of Ananai" legend is a myth elaborated on and spread around by him and Kagami. After a brief battle with Shiina, Seeu arrives to rescue Kaguya and she realizes her love for him. Transforming into a dragon, Gold teleports everyone to Ancient; there Idou, Seeu, Kura, and Shiina are persuaded to combine their magical weapons with Gold to fix the rift in the universe, the cause of the eventual collision between the worlds. The series ends with an epilogue seven years later; Kaguya explains the fate of everyone and meets Seeu and their young son with a picnic basket.
Yuri Narushima stated that she began the manga with "a dramatic feeling in mind " and wanted to "start off with a comic book for young girls (shōjo manga)." Narushima planned to have the plot progress quickly so the reader remembers the events and can "'digest' the foreshadowed events". Planet Ladder was based on the Japanese folktale The Tale of the Bamboo Cutter, which focuses on a girl named Kaguya-Hime who is discovered to be the princess of the moon. Additionally, the protagonist takes her name from the folktale.
After discovering that a North American version of Planet Ladder was being simultaneously released, Narushima designed the cover of volume 6 to be "export friendly", describing it as "like Japanese style, but slightly off". Additionally, she considered serializing Planet Ladder in another magazine, but decided against it since the series was close to ending.
Written and illustrated by Yuri Narushima, Planet Ladder appeared as a serial in the Japanese manga magazine Crimson from March 1998 to May 2003. Sobisha/Shueisha later published the chapters in seven tankōbon volumes from December 1998 to May 2004. Shueisha re-released Planet Ladder in four bunkoban volumes from July 18, to August 8, 2008.
Tokyopop licensed Planet Ladder for an English-language release in North America and serialized it in its manga magazine Smile. The first Planet Ladder volume was released on April 23, 2002; the final volume was published on March 8, 2005. Planet Ladder belonged to Tokyopop's line-up of manga in its original right-to-left format; previously, the majority of manga licensed in the United States was "flopped" to read left-to-right for a Western audience. As a result, it was displayed in a case with the eight other "unflopped" manga—Chobits, Dragon Knights, Marmalade Boy, GTO, Real Bout High School, The Skull Man, Mars and Cowboy Bebop—and heavily advertised in anime magazines and on fan sites. Planet Ladder went out of print on April 2, 2007 in North America.
Only the last two volumes were given titles in the English-language release: The Fate of the Dark Planet for volume six and Ananai of the Puzzled Star for the seventh volume.