Featured Puzzle: Tetoron #1

When Tetris was in its heyday on computers, I was in high school. I’m not sure how many games I’ve played, but I definitely got to the point where I started seeing tetrominoes everywhere. Maybe the inventor of Tetoron, Nishiyama Yukari, was also a fan. In this puzzle, you must divide the grid into tetromino shapes.

• Divide the grid into regions of exactly four cells.
• Each region must contain exactly two different symbols.
• Tetrominoes of the same type must all contain the same two symbols.
• Tetromino shapes may be rotated or reflected.