Puzzle Time at Reunion (再会のパズルタイム Saikai no Pazuru Taimu) is the twelfth episode of Phi Brain: Kami no Puzzle Season One and the twelfth episode of the anime series overall.
Kaito is surprised to meet his childhood friend, Rook Banjou Crossfield , who unbeknownst to him is the head of POG Japan, and learns he is to become an exchange student at Crossfield Academy in England. Upon arriving at the academy, Kaito and Rook spend some time exploring and reminiscing about old times, particularly concerning an old man who taught them about puzzles. While exploring a maze from their childhood, they discover a curious path leading to a Kenja Puzzle. Kaito is trapped inside it and is forced to solve the puzzle while avoiding deadly saw blades. It is soon revealed that this is a more extreme Kenja Puzzle known as the Fool's Puzzle.