I’ve seen the TokyoFlash Retsu watch a couple of times and never fully understood it until now. It’s rather interesting as the timepiece doesn't always display the current time of day.
A button on the TokyoFlash Retsu watch activates the small LED lights in order to relay the time.
There is only one line of numbers (1-10), so the TokyoFlash Retsu watch displays each digit individually, so you have to pay attention. If it is 4:25, then the lights would go to 4, then 2 and then 5.
It’s a very futuristic watch that turns out to be pretty simple and cool in the end.