Piper kadsura (Choisy) Ohwi

Family: Piperaceae
English: Japanese pepper (not to be confused with Japanese pepper vine)
Japanese: フウトウカズラ (姫姫榊, sometimes 姫ひさかき) [Fūtō Kazura]

Fruite ripen into beautiful red balls of pepper, but I've not heard of anyone really using this as a spice. This vine often grows over hedges by coastsa and towns.

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 2012: http://www7a.biglobe.ne.jp/~flower_world/