Japanese companies disestablished in 2006

Radix Ace Entertainment Co., Ltd (Japanese: 株式会社ラディクスエースエンタテインメント, Hepburn: Kabushiki-gaisha Radikusu Ēsu Entateinmento) was a Japanese animation studio closed on October 1, 2006. The studio was formed on September 3, 2001 from a merger between Radix (founded on December 6, 1995) and Zero-G Room (founded on September 11, 1991). Much of the staff from Radix Ace joined Seven or merged with Mobanimation to become Radix Mobanimation in 2007.

KID (Kindle Imagine Develop) was a Japan-based company specializing in porting and developing bishōjo games.

Dia Kensetsu Co., Ltd. (ダイア建設) is a Japanese condominium builder. There are about 2000 condominiums under the Dia Palace brand. The company filed for bankruptcy protection in December 2008.

Punchline is a defunct Japanese company that develops video games. It was founded by former Love-de-Lic employee Yoshiro Kimura and had around 25 employees. Kimura left to work for Marvelous Inc., and later opened a new studio with the name Onion Games.

Takara Co., Ltd. (株式会社タカラ, Kabushiki gaisha Takara) was a Japanese toy company founded in 1955. In March 2006, the company merged with Tomy Company, Ltd. to form Takara Tomy. The Takara motto was「遊びは文化」("playing is culture").

Japan Air System Co., Ltd. (JAS) (日本エアシステム, Nihon Ea Shisutemu) was the smallest of the big three Japanese airlines. In contrast to the other two, JAL and ANA, JAS' international route network was very small, but its domestic network incorporated many smaller airports that were not served by the two larger airlines. As an independent company, it was last headquartered in the JAS M1 Building at Haneda Airport in Ōta, Tokyo. It has since merged with Japan Airlines.

Huser (ヒューザー, Human User Company) was a Japanese real estate agency (a developer) based in Ōta, Tokyo which developed and sold condominiums. Its founder and chairman was Susumu Ojima. Its capital was two hundred eight million yen (2005) and its sales were twelve billion four hundred million yen as of March 2004.

Yellow Dog was a prominent publisher of bootlegs by many prominent artists. The label released series such as "Unsurpassed Masters" (outtakes by many artists, including the Beatles and the Beach Boys) and "Day By Day" (the complete Beatles' "Get Back" sessions). This label has in turn been copied by many other bootleg labels, such as Kiss The Stone and Chapter One. Yellow Dog was shut down in Europe in 2002, but continued to run in Japan until 2006.

Air Hokkaido Co., Ltd. (エアー北海道株式会社, Eā Hokkaidō Kabushiki-gaisha) was an airline based in Hakodate, Hokkaidō, Japan. It operated domestic feeder flights in Hokkaidō from its main base at Hakodate Airport. The airline was dissolved by parent company All Nippon Airways in July 2006.