After he and his entire class are summoned to another world, Hajime Nagumo finds himself extremely underpowered and at the mercy of the Labyrinth.

Hajime's classmates struggle with the aftermath of Hajime's fall. Hajime descends even further into the Labyrinth, where he makes a fateful encounter.

Hajime and Yue descend deeper into the labyrinth, discovering one another's stories along the way.

A rare oasis lies in the depths of the Labyrinth. There, Hajime and Yue come face-to-face with the specter of the labyrinth's namesake.

Several days have passed since Hajime and his party returned safely from the Sunken Ruins of Melusine. Though Hajime knows he needs to get going, he doesn't want to break Myu's heart.

Daisuke and his shadowy co-conspirator overtly take action against Commander Meld, triggering the final phase of their nefarious plan. Meanwhile, Hajime encounters a group of bandits attacking someone he has met before.

With her trap sprung and all of the students rendered unable to fight, Eri reveals her true nature and sets the rest of her plan in motion.