Nanami Hajime, a 'bullied child,' is summoned to another world along with his classmates. While his classmates display special abilities oriented towards combat, Hajime only possesses the ordinary skill of an alchemist. Despite being the weakest in the new world, he is maliciously pushed into a deep dungeon by a classmate. In the depths of despair, with no way to escape, Hajime encounters a vampire named Tsuki, and finds the path to becoming the strongest as an alchemist. 'I will protect Tsuki, and Tsuki will protect me. This way, I am the strongest. I will sweep everything away and surpass the entire world.' The story of the boy who fell into the abyss and the vampire who dwells in the deepest part, working together to create the 'strongest' tale, begins!