This bonus disk was available for purchasers of all Kōnai Shasei vol 1/2/3.
https://aucfree.com/items/c710806139 This website recounts this game was discontinued due to the Saori incident https://en.wikipedia.org/wiki/Saori_(video_game)
The game name on the title screen 校内写生 スペシァル DISK (Konai Shasei Specal Disk) is presumably a deliberate unpronounceable typo.
PC-9801 version screenshots: https://refuge.tokyo/pc9801/pc98/00978.html
