Is Japan in NPT?

Could you please clarify what you mean by "NPT" in the context of Japan's involvement? Are you referring to the Nuclear Non-Proliferation Treaty (NPT), an international treaty aimed at preventing the spread of nuclear weapons and nuclear weapons technology? If so, it's important to note that the NPT is a treaty between states, and Japan is indeed a member of the NPT, having ratified the treaty in 1970. However, if you're referring to a different organization or acronym, please provide more context so I can give you an accurate answer.