If you're full Japanese and was born in USA, would you still be considered as a foreigner in Japan?

Question:

And also if your just half-Japanese would it still be the same.

Answer:

The scenario you present doesn't answer other questions:

You say simply born in the USA, however you do not say if you grew up in the USA etc. TWO very different things. A Japanese parents can have a baby born in America, but move back to Japan (or they were on vacation). This type of scenerio the person generally wouldn't be considered a foreigner, they were born to Japanese in America, but only spent very little time in America itself.

A Japanese person born in America but spent a lot of time in America, but be viewed differently.

You have two different scenerios there.

While anyone born in America has US citizenship, being born of one or even two Japanese parents, the child is also Japanese citizen as well (one does not need to choose the citizenship until age 22 in Japan) and even in that case they might keep both.

Japanese level/fluency plays a very important part as well.