PSO Underground / Kuchiyuku Omoide ni

Year AUW 3087. Three years after explosion of Central Dome life at planet Raguol has finally come to normal state.

Middle-aged Raymar Jay of the Hunters Guild receives a request from his bad buddy to dig information about the infiltration into a small military center three years ago. Together with former lover and friends protagonist challenges the mystery of the lost past.

[From vndbreview]