yes if hes not japanese.
If you are a citizen of a country whose citizen do not need a visa to visit Japan, then you are fine; Green card does not waive visa requirement for Japan.
For a visit of 90 days or less, only a valid passport and return ticket are required.
No, a visa is not necessary, as Japan is in the visa waiver program, but that would require an ESTA from you.
Yes
no
Yes the man from China will need a visa to visit the U.K.
No. The passport is all you need.
No. All you need is your passport.
yes
A passport.
Yes.