Perillula reptans Maxim.

Family: Lamiaceae
Japanese: スズコウジュ (鈴香需) [Suzukōju]

These little white flowers peak out from between the stairs in the trail. I think the deer must like them. Usually there are several flowers blooming on the stalk, but not all the buds bloom at once.

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）