小学校 shougakkou 小 shou means small, here it is equivalent to "elementary"
中学校 chuugakkou 中 chuu means "middle"
高校(short for 高等学校)koukou (koutougakkou) 高 kou means "high" as it is to give higher education. (Same as high school.)
By the way, please write Japan/Japanese in full, as many people (including myself) find the word "jap" offensive.