An interesting point that I might have to add to the notes:
If you read the Toaplan interview with Tetsuya Uemura, he mentions about Data East investing in mushrooms. When you read the DECO interview, they mention other than gas masks, all the other rumors are urban legend.
However, this article as done in probably 2001 or so. Since all the participants had left Data East several years before, they were probably not talking about some of the later investments that might have broken the company. According to Nico Hyakka
they lost heaps of cash on a bad investment in shiitake mushroom cultivation, as well as investments in the manufacturing of minus-ion devices.
Game companies should stick to games. However, it's worth noting they had long since been out of the arcade business, and were pretty much just producing crap at this point. I think it's safe to say Sega would've gone down a similar path had they not altered their tune (instead of changing it altogether). That's the story for another thread, but I think Sega in their current form is better than no form at all.
Other points accordind to the article:
-The interviewer that raised the fuss about Chelnov was forced to resign
According to Wikipedia
The first Deco Game is a "copy" block kuzushi game called Super Break, released in 1976. The second is a "copy" version of Circus, and the third is a "copy" of Space Invaders. Their first original game was Space Fighter, in 1979.
Other than the handful of games in the article, apparently Kuuga 2 (1992) and Touga (1994) were cancelled games, presumably for the arcade. Touga's kanji are "fight" and "fang" (as in Kuuga).
Companies spawned by DECO:
Tecnos Japan: formed by the former managing director, Kunio Taki
Idea Factory: formed by former employees
Work Jam: Formed by former employees, and acquired the Jinzaburo series rights (and continue to make games)
Cattle Call: Formed from former DECO developers (Metal Max 3)
G-Mode: Holds over half the rights of DECO games
Paon: Holds Hercules no Koei rights, and reportedly the Karnof & Chelnov rights.