Follow either the male protagonist Raj — an optimistic adventurer — or Am — a serious sharpshooter — in their quest to protect their homeland, the "Cocoon World" of Fillujah, by defeating the dangerous creatures summoned from an unknown world, Lyndbaum. Along the way, the truth behind the invasion will be revealed.

With the option to choose between two protagonists, the player can decide whom to control in the main story and with whom to have "night conversations." Additionally, there are many well-crafted side events to discover.