[6] In order to compete with northern Kantō region electronics retailers such as Yamada Denki, which were expanding nationwide, EDION entered into business alliances with Osaka chain Joshin Denki (上新電機株式会社, Kabushiki gaisha Jōshin Denki), Kansai region chain Midori Denka (株式会社ミドリ電化, Kabushiki gaisha Midori Denka), Hokuriku region and Hokkaido chain 3Q (株式会社サンキュー, Kabushiki gaisha Sankyū), and Tōhoku region and Hokkaido chain Denkodo (株式会社 デンコードー, Kabushiki gaisha Denkōdō).

The "Voice Network" (ボイスネットワーク, Boisu Nettowāku) was formed by the five companies to plan and develop original products.

However, in 2004, Midori Denka merged with EDION, and the alliance with the remaining three companies was temporarily dissolved.

Listed on the Tokyo Stock Exchange and Nagoya Stock Exchange (TYO: 2730), the head office moved from Nagoya to Osaka from January to July 2007 with the aim of strengthening the foundations of the Kansai region.

On December 10, the Fair Trade Commission approved the merger on the condition that eight of the 10 areas where there are no stores other than those of the two companies would be transferred to other businesses.

On August 26, 2013, EDION announced a capital and business alliance with Lixil Group.

On April 27, 2022, EDION formed a capital and business alliance with Nitori Holdings.