After enjoying his time at his favorite artist's live concert, high schooler and NEET Takumi Hitaro found himself suddenly summoned to the magical world of Doppolia. He discovered a mage named Amada, who accidentally used the teleportation spell on him instead of resurrecting the past hero, Mr. Satori.

Takumi was quickly tasked with defeating a Demon King who threatened their world. He resembled the past hero as his doppelganger. With no way back home, Takumi must help his newly found team and learn about his doppelganger in order to save his new world.