Japan has relatively strict privacy laws that especially prevent companies from using photos for publication without consent. Individuals can make use of some exceptions.
Can I Shoot Footage in Public without Consent?
No, with exceptions. If your photo does not display the subject in a derogatory way, you're allowed to take it.
However, the often quoted court sentence is from 1969 japanese source on wikipedia and the de facto operational procedures of street photographers and photo journalists generaly operates under the assumption that their work is of interest for the public and therefor exempt.
There also is a clause for unjust or probably more accurate unflattering or defamatory use of the image, which depends on which situation the subject is in. Are they vulnerable? Drunk?
Can I publish Photos taken of Strangers without Consent?
No, before publishing you need explicit consent if that picture is a portrait, except if the picture is of interest for the public. The legal grey area is where the protection of the privacy of the individual is more important than the interest of the public.
Again the context of publication is important. Putting a subject on a propaganda poster as the enemy is more likely to get you in trouble.
Can I use Street Photos commercially?
No, you'll not be able to use the photos commercially, see Court Cases for damages paid by infringing parties.
- List of court cases (japanese) regarding the right to a persons own portrait in Japan