Rubus buergeri Miq.

from Korea, Jejudo, 500 m (pictures 1 & 2)
in Japan, Honshu, Kyoto, May 2008 (pictures 3 & 4)
in Taiwan, Fuxing to Qilan Valley, 22 November 2013 (picture 5)

Description in Ann. Mus. Bot. Lugduno-Batavi iii.36