How are mixed people viewed in Japan?

I hear a lot of things about mixed and non-Japanese Asians getting racism. Even my friend who is half got a lot of hle in Japan. Anyway, I'm European, Native American, Armenian and Yakut. Probably if you looked at me, I look like a strawberry blonde Eastern Asian (I guess mainly because my eyes slant and I have high cheekbones) with blue eyes. I lived in Japan for like a month (but it wasn't like work or school so I didn't really like interact with people on a super personal basis). While I was there, I dyed my hair black and one of my friends gave me brown "circle lenses" to try on as a part of a makeover thing. When I had black hair and brown eyes, I used to get asked if I was half a lot. When I had blonde hair and blue eyes, I still get the feeling that they just thought I was Japanese with a dye job. My friend's grandfather upon meeting me told me that Japanese people need to quit dying their hair and that I should dye my hair black too (after I did dye my hair black later, he said that's how Japanese girls are supposed to look). Considering I didn't go out of my way to tell everyone I met I wasn't Japanese or half, I can't really make a decision about race playing a role in how I was treated. So if someone asked my race and I told them, what would they think? Are there a lot of Yakut or Native American people in Japan? Thanks.