Phi-Brain ~ Puzzle of God

Kaito Daimon looks like an ordinary high schooler—until a puzzle appears. Renowned as a “demon” at solving riddles, he’s invited to take a set of “special” tests and immediately senses there’s more being measured than his answers. That suspicion proves warranted when he’s drawn into a lethal Philosopher’s Puzzle engineered by the shadowy organization POG, a maze of traps where a single mistake can be fatal.

Kaito survives the first ordeal thanks to his extraordinary skill, protecting himself and his childhood friend Nanoha, who is swept up in the same deadly game. Marked as a Solver, he’s thrust into a new life alongside other Solvers, traveling far and wide to confront POG’s next high-stakes challenges—each one a strategic battle of logic, deception, and survival.