I've been to Japan several times before COVID. I don't remember ever being asked for an onward ticket. I'm a U.S passport holder.

I'm currently in southeast Asia. I'm not sure yet how many days I'll stay in Japan.. so on the immigration form on Visit Japan Web I just guessed "30 days".

I don't have an onward ticket yet because I plan to buy it later when I'm sure about the date.

Is any onward ticket technically required for U.S citizens? Again, I can't ever remember being asked for it. But I also don't know whether it was ever technically required. Since COVID, I want to see if anything changed.

I put 30 days on the form but it's possible I might stay more than 30 days. In the past, immigration would stamp my passport 90 days regardless of what I wrote. I assume this is still the case?

Thank you for any info