It was founded in 1975 by Yasuhiro Fukushima as Eidansha Boshu Service Center, initially as a tabloid publisher and later attempting to branch into real estate management.

Horii, Nakamura, Toriyama, and Sugiyama would all work on the 1986 role playing video game Dragon Quest for the Family Computer; one of the earliest successful RPGs for consoles, it spawned a franchise of the same name which remained Enix's best-known product.

It also founded the Gangan Comics imprint family, and created international subsidiaries or partnerships related to technology development, publishing, and education.

In the early 2000s, due to rising game development costs, Enix entered discussions about merging with Square, a rival company known for the legendary Final Fantasy franchise.

[1] An architect-turned-business entrepreneur, Fukushima initially founded Eidansha as a publishing company focused on advertising tabloids for real estate.

Fukushima decided to invest his capital into the emerging video game market; during this period on August 30, Eidansya Fudousan was renamed Enix Corporation.

[3]: 84–89 [13] While meeting with initially slow sales, Dragon Quest became a critical and commercial success, selling over one million copies in Japan.

[7] While the Dragon Quest series proved successful, Enix continued publishing PC titles to maintain financial stability.

[3]: 77–81  The company also began selling merchandise themed after Dragon Quest in 1988 with character statues and toys, expanding to board and card games the following year.

[7] In the years following, Chunsoft continued collaborating with Enix on spin-off Dragon Quest titles including early entries in their Mystery Dungeon franchise.

[30] Enix later acted as publisher for Star Ocean (1996), developed by former Tales of Phantasia staff members who split from Wolf Team to form tri-Ace.

[41][42] Editor Yoshihiro Hosaka and a number of other Gangan associates founded Mag Garden in 2001, which became a market rival through the Monthly Comic Blade magazine.

[43] Mag Garden's foundation triggered a mass departure of creatives and legal battles with Enix over manga copyright ownership.

[52] Despite this, some shareholders had doubts about the merger, notably Square's founder Masafumi Miyamoto, who would find himself holding significantly less shares and having a smaller controlling stake if the deal went ahead as initially planned.

[54][55] Enix's last two published titles were Star Ocean: Till the End of Time and Dragon Quest Monsters: Caravan Heart, both in 2003.

[18] Horii notably created Armor Project as a company to oversee Dragon Quest for Enix, with him comparing the relationship to that between an editor and an artist.

The subsidiary came into existence in 1990, but closed in November 1995 when the parent company decided to no longer release products in North America[66] due to poor sales.

[78] Hosaka also credited Enix with introducing fantasy into the wider mainstream market, and as a pioneer of publishers directly investing in and having creative input into anime adaptations of their work.