In this commentary, we wish to briefly draw the international architectural community’s attention to an ongoing urban development struggle taking place in a highly historical and popular green zone in the heart of Tokyo, the Meiji Shrine Outer Garden, or Jingu Gaien Park. A proposed 13-year development project by Mitsui Fudosan Group, and with tacit support by the Tokyo Metropolitan Government, may threaten the socio-cultural stability and perpetuity of Jingu Gaien Park. In the absence of a sound environmental impact assessment, and enough public participation, not only will an imbalance in the historical and cultural heritage occur, amplified by gentrification, so too might there be a negative impact on natural and environmental aspects of this historic site.