This post is the first part in a series of challenges designed to improve the knowledge and awareness of fake Japanese coins (both cast and struck) among collectors. The objective is to determine which coins are fake and which coins are real. Post your response in the comments (each coin is marked with a letter in the upper-left corner) and why you think each coin is either real or fake. After some people have responded, I will post the correct answers in the comments. Some of the coins may have problems, which could make them seem fake!