||The OPU–TKU Joint Symposium has been held annually between Osaka Prefecture University (OPU) and Tamkang University (TKU) in rotation fashion for 5 years since 2013. These include the first meeting in Osaka, Japan, in 2013; the second in New Taipei City, Taiwan, in 2014; the third in Osaka, Japan, in 2015; the fourth in New Taipei City, Taiwan, in 2016; and the fifth in Osaka, Japan, in 2017. In order to expand the scope of this meeting and recruit more outstanding scholars, the founder of this symposium, Prof. Masakazu Anpo (the former Academic Vice President of OPU), suggested inviting more colleges, especially from Vietnam, to participate OPU–TKU Joint Symposium. For this reason, universities such as HCMUT (HCM City University of Technology), DLU (Dalat University, Dalat City), and TNU (Tay Nguyen University, Buon Ma Thuot City) were invited to be the members of this joint symposium. Hence, it is appropriate to change the title of the symposium from the OPU–TKU Joint Symposium to the 6th TKU–OPU–HCMUT–DLU–TNU Joint Symposium on Chemistry and Natural Sciences (JSCNS-6). The first JSCNS-6 has been held at Tamkang University (TKU) in New Taipei City, during Nov. 22–24, 2018.