Hajime and his classmates are summoned to another world, but his crafting role leaves him dismissed beside their more powerful abilities. After falling into a dungeon’s depths, he must find his own way to survive. His escape develops through improvised power and an alliance with the imprisoned vampire Yue.
When Hajime and Yue meet, both have reasons to distrust others. Their early cooperation combines his changed abilities with her vampire power, and she points him toward a possible route back to the surface. The partnership gives the dungeon escape a shared objective before the larger travelling party forms.
Kaori Shirasaki is one of the classmates carried into the new world with him, and her assigned role is healer. She refuses to assume that his fall means he is dead and acts on the belief that they can meet again. While Hajime forms an alliance with Yue below, Kaori keeps a connection to the class he has been separated from.