A small and largely deserted island in Japan’s Seto Inland Sea has unexpectedly become the centre of growing geopolitical tension between Tokyo and Beijing, highlighting broader concerns in Japan about foreign ownership of land in strategically sensitive locations. Kasasa Island, home to only seven registered residents, has recently drawn national attention after Chinese investors purchased and began developing land on the island, raising suspicions among locals and policymakers about possible security risks.
Kasasa, often described as the “Hawaii” of Japan’s inland sea because of its mild climate and scenic coastline, is less than one square kilometre in size. Despite its idyllic environment, the island holds strategic significance because of its proximity to important military facilities. The Iwakuni US Marine Corps airbase lies roughly 20 kilometres away, while a base of the Japan Maritime Self-Defence Force is located about 50 kilometres to the north in Kure. This geographic position has made the island particularly sensitive from a national security perspective.
For decades, Kasasa remained a quiet retreat inhabited by a handful of residents who rely largely on fishing and small-scale farming. Among them is 80-year-old resident Hideya Yagi, who moved to the island more than two decades ago in search of a peaceful life. However, the tranquillity of the community was disrupted after reports emerged that Chinese developers had legally purchased two plots of land on the island through a Japanese real estate company. The purchase itself complied with Japanese laws, but construction activities that began recently—including the arrival of heavy machinery and installation of power infrastructure—have triggered speculation about the investors’ intentions.
Local residents say they were initially told the land might be developed for tourism purposes, such as holiday homes, restaurants or cruise facilities. Yet the sudden commencement of construction after years of inactivity has fuelled uncertainty. Residents worry that the island’s isolated location could potentially allow activities such as surveillance without attracting much attention, given the extremely small population.
The issue has quickly evolved from a local concern into a national political debate. Conservative politicians and activists have warned that increased foreign ownership of land near strategic locations could threaten Japan’s security interests. Some have even suggested that islands like Kasasa could theoretically be used as bases for monitoring nearby military installations. Although experts point out that existing Japanese laws apply equally to domestic and foreign landowners, the situation has intensified calls for stricter regulations.
Japanese Prime Minister Sanae Takaichi has responded by pledging tighter oversight of land purchases in sensitive areas, reflecting a broader shift in Japan’s approach to national security. The debate has also unfolded against a backdrop of deteriorating diplomatic relations between Japan and China. Tensions between the two countries have increased in recent months, particularly after statements from Tokyo suggesting Japan could become involved militarily if a conflict broke out over Taiwan. Beijing reacted strongly to those remarks and imposed export restrictions on certain goods destined for Japanese companies involved in military supply chains.
Meanwhile, residents of Kasasa say their main concern is preserving the island’s peaceful environment rather than fuelling nationalist sentiment. Community groups have even proposed buying back the disputed plots and encouraging new residents to move to the island in order to revive the shrinking population. Once home to around 100 people before the second world war, Kasasa now has dozens of empty houses and abandoned buildings.
As geopolitical tensions continue to shape regional politics in East Asia, the fate of this tiny island illustrates how even the smallest and most remote locations can become entangled in the broader strategic rivalry between major powers. For the few residents who still call Kasasa home, however, the priority remains simple: preserving their quiet way of life on an island that until recently existed far from the world’s political spotlight.
