Kei Furutsuki / ふるつき景 was a pen name he used for both his video game-related work and the illustrations he drew for a motorbike magazine. He used another pen name - Bright - for his amateur comics (Evangelion, Gundam, etc.).
I don't know if he worked on other games between 1990 and 2005, I don't yet know the name of the magazine he worked for and his real identity is also unknown to me. His wife (to whom we owe much of the information in this thread) also worked as a video game background designer.
He started a blog in 2008, which is still online and has hundreds of posts (not all of which I've read yet). According to his first post, he was a freelance illustrator in Hiroshima, although he is credited as a member of the company インクライン (Incline / Ink Line?) with other artists who, like him, were in charge of drawing the backgrounds for at least 5 visual novels produced between 2006 and 2009.
He died of liver cancer on December 3, 2010.
Sources:
https://vndb.org/s31311
https://www.mobygames.com/person/199022/kei-furutsuki/
https://ameblo.jp/bright2008/entry-10135133489.html
https://x.com/MayLilyfairy/status/739679292997570562
https://x.com/MayLilyfairy/status/905409971180888064
https://x.com/MayLilyfairy/status/778874735761371136
Aleste / アレスタ (MSX2 - 1988)
Cover art, manual illustration(s) (Source: credited in an ad)
Aleste 2 / アレスタ2 (MSX2 - 1989)
Cover art, manual illustrations (Source: credited in the manual)
Promotional illustration (Source: credited in an ad)
Final Approach 2: 1st Priority / Φふぁいなる・あぷろーち 2 〜1st priority (PS2 - 2008)
Backgrounds (Source: in-game credits)
Nettai Teikiatsu Shōjo / 熱帯低気圧少女 (PS2, Windows - 2007)
Backgrounds (Source: in-game credits)
Shin Maō Golvellius / 真・魔王ゴルベリアス (MSX2 - 1988)
Cover art, manual illustrations, opening and ending illustrations (Source: in-game credits. Sketches for the cover art and the manual cover: Compile Club Vol.13 - November 1988)
Souten no Kanata / 蒼天の彼方 (Windows - 2009)
Graphics, coloring (Source: in-game credits)
Yumemi Hakusho: Second Dream / 夢見白書 Second Dream (PS2 - 2008)
Backgrounds (Source: in-game credits)
Yumemishi / 夢見師 (PS2 - 2006)
Backgrounds (Source: in-game credits)
Aleste
Aleste 2
Shin Maō Golvellius
misc