Monster Strike: Deadverse Reloaded

Ren Homura returns to his hometown of Kaminohara and struggles to recall his past. He retrieves his repaired cell phone and discovers a mysterious game called Monster Strike installed on it, which he had no knowledge of. After opening the game, Ren is attacked by a man on the roof of his school, which has been designated as a "stage" in the game, and the man summons a realistic monster. Ren decides to summon Oragon, a dragon from the game, to aid him, but it turns out to be a small and ineffective dragon.