Even though you speak the Japanese language, they don’t see you as a Japanese person
Japanese people don’t really see you as Japanese, even if you can speak Japanese. From my own experiences, if my intonation’s a bit off, or my phrasing’s a bit odd, no one will mention it directly but I still feel as though I’m being watched. I suspect foreigners who live in Japan have also felt the same thing. The media gives off the same feeling. There are celebrities who sell themselves as being half-Japanese, but I think in the end, I don’t think they’re perceived as actual Japanese people.