''Ypthima masakii'' is a
butterfly in the family
Nymphalidae (subfamily
Satyrinae
The Satyrinae, the satyrines or satyrids, commonly known as the browns, are a subfamily of the Nymphalidae (brush-footed butterflies). They were formerly considered a distinct family, Satyridae. This group contains nearly half of the known divers ...
). It is
endemic to
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
. The type locality is on the
Loochoo Islands.
References
masakii
Butterflies described in 1947
{{Satyrini-stub