Growlanser: Heritage of War is a tactical role-playing game, the plot of which unfolds over two generations on a mysterious island-continent, immersed in darkness and shrouded in an impenetrable veil. Its inhabitants are fighting an ongoing war for survival, caused by a famine that has left the land barren. In this turmoil, users manage a real-time combat system that requires quick thinking and strategic skill to cope with difficulties. The storyline begins with the Peacekeeping Brigade, armed with the ancient weapon Admonisher, seeking to end the conflict by force. Brigade leader Seldus is married to Vanetta and they have a son, Krious.

Two decades have passed and the Brigade's ability to maintain peace is crumbling, leading to renewed war between the continent's factions. The narrative moves smoothly from one character to another, including Krios, who serves as the Brigade's diplomat, and Fanil, an explorer seeking to unravel the mysteries of the ruins of an ancient civilization. As players progress through Growlanser: Heritage of War, they are given the unique opportunity to form close relationships with various characters, which will have an impact on how the story unfolds. Developing relationships add an additional level of complexity to the gameplay, allowing users to determine the outcome of the plot.