Tokumei Kachou Ijuuin Ginzaburou

Japan is devastated by the eruption of Mt. Fuji in 2010. A huge casino is built on the ruins of the city under JCP company. Main character is JCP intelligence agent tasked to prevent hostile companies plotting against JCP. Hero knows special technique from ancient India to make girls fall for him in an instant, and he utilizes it against females of the rival corporations to learn their scheming and secrets.

[From vndbreview]