Ren Homura returns to his former residence, yet he feels very uncomfortable: he possesses no memory of having lived there. Without warning or his permission, a game called "Monster Strike" installs itself into Ren's smartphone; monsters of the game then literally fly out from his smartphone and start fighting on streets. Watching the fighting in amazement, Ren starts picking up his lost memories.
Ren returns to the town of his childhood, Kaminohara. Strangely, Ren is unable to recall any memories of the town. Meanwhile, his smartphone installs a mysterious game called Monster Strike — heralding the start of...
Ren is forced into a heated battle with the bestial Fenrir X. Unable to control his companion Oragon and on the verge of defeat, a girl appears before Ren. Who could she be?
