With the facilitation of globalization and technological advancements, the growing complexity of global issues has expanded the spatiotemporal scope of their impact. In international relations, sub-units beneath the primary actors – states – have emerged as critical actors with a demand for effective and real-time responses to global affairs. Transgovernmental network governance, operating by the sub-units in a decentralized and centrifugal architecture, has emerged as a diverse and flexiblegovernance model that transcends interstate interactions. Simultaneously, international regimes have expanded based on small-scale cooperation. When niches exist in specific issue areas, major powers have initiated the construction of transgovernmental network governance, positioning themselves as pivotal actors. In the realm of space governance in Asia, China and Japan have each established transgovernmental network governance mechanisms promoting capacity building and cooperation centred around themselves – the Asia-Pacific Space Cooperation Organization (APSCO) and the Asia-PacificRegional Space Agency Forum (APRSAF). Case studies of the aforementioned organizations further reveal that when plural transgovernmental networks operate within the same issue area, the governance landscape takes on a derived form of coexistence between competition and cooperation, which is the transgovernmental network governance of “co-competition.” Across multiple analytical levels, such characteristics indicate a flexible space of proliferation, expansion, and transformation.