Short selling American option?

If you shorted American option, would it be like you suddenly have to sell (call) or buy (put) it when the buyer exercised its right? But there are thousands of buyers and sellers in the option market. So I wouldn't have any idea who is the buyer of my option even if I short sold it, would I? The only... show more If you shorted American option, would it be like you suddenly have to sell (call) or buy (put) it when the buyer exercised its right?

But there are thousands of buyers and sellers in the option market. So I wouldn't have any idea who is the buyer of my option even if I short sold it, would I?

The only option in my country, Japan, which has substantial volume is Nikkei 225 Index option. And it's European option. We can hold the short position until the expiration date. So I don't know what it's like to short American option.

Please tel me what it's like to short American options.
Update: Leo Enoch. Suppose there is option of AA stock. I shorted it its put $50 (strike price) at $1. If the buyer of my short position bought it at $0.10, it's likely that he exercise it when the stock is at $49.50 because it could make $0.40 profit. On the other hand, if the buyer bought it at $1, it's... show more Leo Enoch. Suppose there is option of AA stock. I shorted it its put $50 (strike price) at $1. If the buyer of my short position bought it at $0.10, it's likely that he exercise it when the stock is at $49.50 because it could make $0.40 profit.

On the other hand, if the buyer bought it at $1, it's unlikely that he exercise it when the AA stock is at $49.50 because it would make $0.50 loss.

So knowing the buyer enables me to anticipate when it could be exercised.
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