Rubus parvifolius L.

Family: Rosaceae
English: Small-leaved raspberry, Australian raspberry
Japanese: ナワシロイチゴ (苗代苺) [Nawashiro Ichigo]

A low-growing rasberry with purple flowers that never seem open, followed by small clusters of large berries. (In contrast, an internet search of Rubus parvifolius also returns descriptions of the North American plant called 'thimbleberry' with larger leaves and larger, white, fully-opening flowers.)

References:
九州野山の花 片野田逸朗,2004：南方新社
米倉浩司・梶田忠 (2003-)　「BG Plants 和名－学名インデックス」（YList），http://ylist.info（ 2019年8月14日）
Prof. Summer's Web Garden: Referenced 2016 from http://treeflower.la.coocan.jp/Rosaceae/Rubus%20parvifolius/Rubus%20parvifolius.htm