From the perspective of a civil engineering student studying in Japan, here is some information about the master's and doctoral programs.
In Japan, a master's degree can be obtained in two years, and a doctoral degree is mostly obtained in about three years. The first year of a master's degree focuses on taking lectures and obtaining most of the required credits. In the second year, the main task is the master thesis. The number of credits required for a doctoral program may vary depending on the school, but in any case, lectures are few and far between, and almost all the effort is devoted to research and academic papers.
The research lab I belong to consists of senior students, master's students, PhD students and supervising professor. Senior and master's students conduct their studies and research in large public research rooms that can accommodate a dozen or even dozens of people. PhD students generally have small offices for two to four people. And my research lab has weekly seminars about research plans, experimental progress, reference sharing, book reports etc. And in addition to lab-scale experiments, there will be opportunities to go to the field for research. In short, in the daily research life, there are many opportunities to communicate with teachers, fellows and classmates, the sense of belonging is strong, which will make people full of research motivation.