The Challenge Letter. Word Search Puzzle Solver. The Challenge Letter word Search Puzzle Game. Find words related to movie actors, actresses, and genres. Word Search Puzzle Solver. A Japanese martial artist Tomioka sends out the challenge letter to the world class martial artists all over the world to challenge them to become the strongest martial artist in the world. This includes identifying and searching for words that are related to : Action, Robert Chen, Nobuaki Shimamoto .