Yes, SHIMADAI Securities is a legitimate broker regulated by the Financial Services Agency (FSA), Japan's main financial regulatory body. This provides a certain level of security and confidence that the broker operates under established financial laws. The FSA requires firms like SHIMADAI to follow regulations on client fund protection and disclosure. However, the lack of information on trading platforms, and the absence of a demo account may be a concern for potential traders. Traders should weigh the pros of regulation with the cons of limited platform functionality and language barriers before deciding to trade with SHIMADAI.