A quick question,
Are Foreigners protected by law if they need to defend themselves against an assault from a Japanese person or another foreigner, and/or protect another person from an assault?

Will it simply be viewed as fighting and the verdict be against the foreigner who defended themselves?

Although it is highly unlikely that a Foreigner who is respectful of the culture and the law will get into a fight while they are in japan, it can be possible to be in the wrong place at the wrong time. With a chance that you may not be able to run anywhere and might end up backed into a corner, even after you have tried to reason with them in a calm and discrete manner.
Also with foreigners having a bad reputation for violence, some witnesses could assume the foreigner provoked the attack.
What would be the probable outcome if this happened?