Fermat's last theorem. The most difficult problem in mathematics has fascinated mathematicians all over the world for 350 years. In 1951, in post-war Japan, there was a young mathematician who took on the challenge of proving the devil. His name is Andy Homura. His life and the history of the mathematical world begin with the appearance of a great genius, a young girl named Llama. The proof that Homura's entire life is at stake begins.