Yes, MARUSAN is a legitimate broker, as it holds a retail forex license from the FSA. This indicates that the broker has met the necessary standards set by the regulatory body to offer financial services in Japan. From my experience, having an FSA license ensures a high level of credibility and safety. However, since MARUSAN specializes more in asset management than active retail trading, I would suggest assessing if their offerings meet your specific trading or investment needs before making a commitment.