The manga was adapted into an anime television series by Victor Entertainment, which was taglined Quack Experimental Animation. Directed by Shinichi Watanabe and featuring animation from J.C.Staff, the series premiered on TV Tokyo in 1999. TV Tokyo only aired twenty-five of the series’ twenty-six episodes, with the finale having been intentionally made too violent, obscene and long for broadcast on Japanese TV. As such, it was only included in the DVD release of the series, although it has since been broadcast in other markets.
Victor Entertainment contacted Shōnen Gahosha about adapting Excel Saga into an anime, and the two companies approached Rikdo. Shinichi Watanabe was chosen as director. Watanabe added his own alter ego, Nabeshin, and expanded several elements. He says that the Great Will in the manga was “conveyed just as words,” and he himself developed its appearance, eventually settling on the “swirling, talking cosmos.” He also increased Pedro’s role in the story from a single frame in the manga. Watanabe says he was pleased with that aspect of his work, noting that “Pedro’s situation was considered unsuitable for broadcast in Japan”. The anime production staff was given the freedom to do anything they wanted as long as they kept the theme of the series intact, and Rikdo requested they created a separate timeline. Rikdo would later become influenced by the anime series due to its quick broadcast in comparison to the monthly schedule of the manga. The anime makes frequent use of parody and in-jokes as comedic devices, with each episode having a genre-based theme. This extends to the animation, with several characters designed in the style of other works, such as those by Leiji Matsumoto. Kotono Mitsuishi was chosen to play the role of Excel, and Watanabe was impressed with Mitsuishi’s rapid delivery of her lines, saying that “she really pushed herself to the limit and beyond.” He also says, “at times she was too fast, and there was plenty of time left to match the lip-synch”. In such cases, either he would add new material or Mitsuishi would ad-lib. At first Rikdo felt stunned and uncomfortable at hearing Excel speak, but he called the casting “amazing” and was pleased to hear his favourite voice actors read lines from his work.
An anime adaption was produced by J.C.Staff and directed by Shinichi Watanabe. Twenty five episodes were broadcast on TV Tokyo between October 7, 1999 and March 30, 2000. At the publisher’s request, the anime series follows a different storyline from the manga, however Rikdo was pleased with the adaptation. Victor Entertainment produced the music of the series, which was composed and arranged by Toshio Masuda and directed by Keiichi Nozaki. Director Shinichi Watanabe wrote the lyrics for the opening and closing themes,. The opening theme which were performed by Yumiko Kobayashi and Mikako Takahashi who were credited as The Excel♥Girls . The lyrics for the opening theme Love (Loyalty) were written “on the train, five minutes before the deadline”. The closing theme was Menchi’s Bolero of Sorrow The two themes were released together as a CD single on November 3, 1999.
A twenty-sixth episode, Going Too Far, was deliberately created to be too violent and obscene for broadcast in Japan and was instead included as a DVD bonus. Watanabe commented that it “felt good to go past the limits of a TV series”, although he thinks it “is not something that you should do too often”. In Japan the series was released on 12 DVDs between March 1, 2000 and January 24, 2001.
The series was licensed for an English language release in North America and the United Kingdom by ADV Films and in Australia and New Zealand by Madman Entertainment. The English adaptation initially starred Jessica Calvello, with Larissa Wolcott taking over the role after episode thirteen after Calvello had damaged her voice during production. In North America, ADV released the series on six DVDs between June 11, 2002 and April 8, 2003. A complete collection of the series was released on July 6, 2004 as Excel Saga – The Imperfect collection and re-released in different packaging on August 1, 2006 as Excel Saga – Complete Collection. In the UK, the series was first released between May 19, 2003 and March 15, 2004. A complete box set was later released as Excel Saga – Complete Box Set on July 2, 2007. The UK license for the series expired in January 2008. The series was broadcast on UK TV channel Rapture TV from January 2, 2007.
On October 30, 2010, Excel Saga was re-licensed in North America by Funimation Entertainment, who re-released the complete series to DVD on May 17, 2011.