Beneath it lies the single stroke of One, flat as the tatami floor.
The wand taps down, and suddenly the stroke sinks “下”-meaning below-like a subway (地下鉄, chikatetsu) diving under the city.
From the shadows rise Namahage demons, storming villages “from below,” their drums echoing ka–ge (the on’yomi readings).
Whenever you see 下, remember: wand above, One below-together pointing to everything that lies underneath.