It's a sans-serif typeface (called "gothic" typeface in Japanese), which is commonly used for signs, and stroke order/direction isn't so visible without serifs.

It's a sans-serif typeface (called "gothic" typeface in Japanese), which is commonly used for signs, and stroke order/direction isn't so visible without serifs. But the design still implies stroke order in some cases, e.g. with round corners suggesting a single stroke, and sharp corners suggesting two strokes. Some of the signs are written in "round gothic" style where this distinction is dropped, but round gothic is still a normal style. The strong alignment of the strokes to a grid is somewhat unusual, and the article explains how it's a result of the production technique. It's a good example of technical limitations fostering creativity. It reminds me of pixel art, where limited resolution forced development of new techniques that ended up being aesthetically appealing in their own right. The need to make clearly legible signs with limited equipment in a busy train station produced a distinctive style that wouldn't have happened without these constraints.