黑潮

[ noun ]
a warm ocean current that flows northeastwardly off the coast of Japan into the northern Pacific ocean
<noun.phenomenon>

Japan current \Japan current\
A branch of the equatorial current of the Pacific, washing
the eastern coast of Formosa and thence flowing northeastward
past Japan and merging into the easterly drift of the North
Pacific; -- called also {Kuro-Siwo}, or {Black Stream}, in
allusion to the deep blue of its water. It is similar in may
ways to the Gulf Stream.
[Webster 1913 Suppl.]