Eurya japonica Thunb. var. japonica

Family: Ternstroemiaceae
Japanese: ヒサカキ (姫榊, sometimes 非榊) [Hisakaki]

I often find this evergreen shrub growing near the small shrines on Outer Mountain peaks and in sunny spots along the trails at middle elevations. It has a strong scent when in flower that puts some people off. For a good read, see Mosquin, D. Eurya Japonica (2013) Botany Photo of the Day, UBC Botanical Garden Centre for Plant Research.

References:
Mosquin, D. Eurya Japonica (2013) Botany Photo of the Day, UBC Botanical Garden Centre for Plant Research http://botanyphoto.botanicalgarden.ubc.ca/2013/03/eurya-japonica.php
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）
九州野山の花 片野田逸朗,2004：南方新社