The month of October, 2021. Two months have passed since a group of five high school students, expecting a vacation on Ryuusei Island, have instead uncovered a secret: a cold war behind the scenes, in motion since the days of the incident more than a year ago which revealed the existence of the island to the outside world.
The two sides of the conflict: a secret group, watching over the island and keeping its hidden secrets from being used by the wrong hands, the Akasaki clan; on the other, a start-up research group headed by one named Engi Raiya, who seems to be on an urgent race against time to uncover the secret of what shouldn't be on the island in the first place... a deposit of mysterious crystals. Little did they know a third competitor was about to emerge, another group who's willing to do anything to get their hands on whatever the island has hidden.
Recently, a leading figure in a case against the now-bankrupt Arcanum Corporation has emerged. A person who was missing since the incident, whose activities between then and now are yet unknown. This person has set his sights on Ryuusei Island for some reason...
...you are one of the investigators assigned to this case. Your objective is to figure out why this person has emerged from hiding and what he intends to do once he sets his operations on the island.
The power of the crystal beckons to one who searches for it.