Research-based universities have played a significant role in the economic growth of nations, particularly in the United States, where companies originating from these universities have generated substantial employment opportunities and revenue. There exists a substantial disparity in the number of spin-off companies created from these universities between the United States and Japan. Although Japan is not far behind the United States in terms of patent numbers, it significantly lags behind in successfully commercializing research outcomes through the establishment of startups. Therefore, this thesis focuses on the Massachusetts Institute of Technology (MIT), a leading institution in spin-off creation in the United States, and the University of Tokyo, the leading institution in Japan. The objective is to investigate how their university-based ecosystems, including university-supported venture capital initiatives and on-campus entrepreneurship programs, influence the establishment of university spin-offs. The analysis is conducted through interviews and a literature review to examine the impact of these ecosystems on the formation of university spin-off startups. Many of the spin-off startups emerging from research-based universities fall under the category of "deep tech" companies, which are based on long-term research outcomes and require substantial investments and development time. Consequently, a funding gap referred to as the "valley of death" arises, presenting a unique financial challenge for entrepreneurs between research invention and commercialization. It is essential for entrepreneurs to overcome this funding gap, and thus, we also investigate how university spin-offs in Japan and the United States make fundraising choices to bridge the capital gap. By conducting these surveys, we aim to gain insights into the effectiveness of university-affiliated venture capital firms, university spin-off startups, and the overall university ecosystem.