Let's Begin Puzzle Time! (パズルタイムの始まりだ！ Pazuru Taimu no Hajimari da!) is the twenty-fifth episode of Phi Brain: Kami no Puzzle Season One and the twenty-fifth episode of the anime series overall.
Rook presents a solar system based puzzle where, if Kaito reaches the Sun, Rook would fall to his death, with Rook simplifying the puzzle to make it easy for Kaito to solve. Kaito, looking for a way to solve the puzzle while saving Rook, realizes he can get help from his friends. Realizing that the puzzle is based on the wooden puzzle Rook made him ages ago, Kaito manages to save Rook by stopping the Sun from crumbling while the others use a bomb to steer Kaito and Rook to safety. As Rook realizes he wants to make more puzzles for fun, his Orpheus bangle disappears, and he decides to go on a journey to find himself and reform the POG.