下　中　月　火　木

下 is the mirror twin of 上 (above). It shows a short stroke or dot placed below a baseline — directly pointing downward. The ancient form was a vertical dash hanging beneath a horizontal line, one of the simplest direction markers in the writing system.

中 shows a vertical line piercing through the exact center of a rectangle. Ancient interpretations suggest it depicts a flag or pole planted in the middle of a field to mark the center of a territory. The line divides the space perfectly in half — defining what is 'inside' or 'middle'.

月 is a pictograph of the crescent moon. The ancient form clearly showed a curved crescent with a line inside — distinguishing it from 日 (sun), which was a full circle. The two inner strokes represent the glow or shadow of the moon's surface. Because months were measured by the lunar cycle, 月 also means 'month'.

火 is one of the most vivid pictographs — a direct drawing of flames leaping upward. The ancient form showed a central pillar of fire with two curved tongues of flame spreading to each side, like a campfire viewed from the front. The modern character still carries that dynamic, upward energy.

木 is a beautifully clear pictograph of a tree in full profile: the vertical stroke is the trunk, the horizontal stroke is the spreading branches, and the two downward strokes at the bottom are the roots reaching into the earth. This same character is the base for 本 (root/book) and 末 (tip/end).