A small island, called Esanbe Hanakita Kojima, has unexpectedly vanished off Japan's northeast coast. The mysterious disappearance has prompted Japan's coast guard to search for the island.
Authorities are also planning a survey to determine if the island has indeed been washed away.
"It is not impossible that tiny islands get weathered by the elements," a coast guard official said.
The coast guard official said that the missing island "may affect Japan's territorial waters a tiny bit", but only "if you conduct precision surveys".
The small outcrop was previously found some 500 meters off a village called Sarufutsu on the northern tip of Hokkaido island, Japanese daily Asahi Shimbun reports.
The tiny island was only officially surveyed and registered by the country's coast guard in 1987, who couldn't even say how big it exactly was.
Although, recently it rose 1.4 metre above sea level, it was even visible from the tip of the northern Hokkaido island of Japan.
Japan, which is prone to earthquakes and severe weather, has found itself not only losing, but sometimes gaining territory due to natural disasters and extreme weather.
A 300 metre strip of land emerged from the sea and attached itself to Hokkaido's coast in 2015.
The phenomenon initially raised fears of unexplained seismic activity, but geologists said it was probably the result of a landslide that pushed the underwater surface up.
But in 2013, a volcanic island appeared around 1,000 km south of Tokyo, engulfing an existing island and continuing to grow, according to global media reports.
Japan pours resources into protecting its outer islands, particularly the remote Okinotori islands in the Pacific, which secures a significant portion of the nation's exclusive economic zone.
It is also locked in disputes with neighbours, including China and South Korea, over the sovereignty of several islands in the region.
