Institute of Technology Bandung (ITB), Indonesia and Gunma Astronomical Observatory (GAO), Japan have been proceeding with several programmes of mutual collaboration in the fields of astronomical research and education since 2002. ITB with Bosscha observatory has a great interest in education of astronomy for public people as well as in the university education and research of their own, and GAO is a public observatory operated by Gunma prefecture local government equipped with a 150-cm reflector and some smaller telescopes, which are capable of scientific research of high grade. We will report some of our cooperative activities including the remote accessing of the telescopes of each observatory by each other, which can provide opportunities for astronomical experiences of the opposite hemisphere for various people of each country. Some scientific collaboration works such as common instruments and data analysis systems developed on both sites are also reported.