Many of the Japanese resellers list huge volume, often at inflated prices. I assume the volume is what limits their ability or desire to provide a description and they manage to sell in sufficient numbers even with the often high price and average-poor quality.
The occasional benefit is that you can find a very good watch at a reasonable price but the hit ratio is 1:1000.
It’s also worth noting that Japanese sellers often don’t have the watch in hand. They’re drop shipping from other resellers so can’t answer questions or provide additional information.
As Dan says. You can occasionally find good deals but returns are difficult so you’ve got to know your onions and accept a level of risk.