Part time english/japanese jobs for under 18s?

I'm 17 and I have a japanese citizenship and i recently came over to Japan to find work during my gap year. I speak english fluently and I can speak Japanese really well but my reading and writing is not that good. I've applied for many jobs, especially those that want english speakers but i get turned down quite often. I've gone to a lot of interviews as well but i think they see my bad reading and writing skills and decide that they'd rather have someone more literate. Are there any other jobs I could maybe try apply to?