Arifureta: From Commonplace to World's Strongest

Arifureta: From Commonplace to World's Strongest (also known as Arifureta Shokugyou de Sekai Saikyou) is a classic isekai anime with a dark twist on the "transported to another world" trope.

The story follows Hajime Nagumo, an ordinary, somewhat bullied high school otaku with no special talents. One day, his entire class (including himself and their teacher) is suddenly summoned to a fantasy world called Tortus, where they're tasked with becoming heroes to fight against demons in a war.

While his classmates receive powerful combat-oriented abilities and heroic stats from the summoning, Hajime gets stuck with a seemingly useless transmutation skill (Synergist class) that's good for crafting but weak in direct fights. He's mocked and looked down upon as the weakest in the group.

During a dungeon exploration in the Great Orcus Labyrinth, a betrayal by one of his classmates leaves Hajime abandoned and plummeting into the abyss of the dungeon, presumed dead. Facing starvation, monsters, and despair, he barely survives and undergoes a brutal transformation—both physically and mentally. He becomes ruthless, resourceful, and obsessed with getting stronger, evolving his abilities in extreme ways (including eating monsters to gain their powers) to claw his way back to the surface and eventually seek revenge/revenge on those who wronged him.

The series follows his journey from "commonplace" weakling to becoming overwhelmingly powerful ("world's strongest"), gathering a group of loyal (and often devoted) companions along the way, conquering labyrinths, challenging gods, and pursuing his goal of returning home—while no longer being the same naive person he once was.

It's known for its over-the-top power fantasy elements, edgy protagonist development, harem aspects, and themes of betrayal, survival, and revenge. The anime has multiple seasons (with Season 1 often criticized for animation quality, but the story picks up in later adaptations).