Datam Polystar Co., Ltd. 制作的 Galgame

Datam Polystar Co, Ltd. was a Japanese media company founded on 30 May 1990 headquartered in Chiyoda, Tokyo. After the release of the album Takemoto Izumi Uta Kore in 2009, the company became dormant until it was fully dissolved and liquidated on 7 February 2019. [from Wikipedia]