In addition to Ishiwata and Tange, Japan had several fork and frame fitting manufacturers including Eisho, Kobayashi, Miwa, Nikko. Otsuya, Sanya and Yamazaki. I imagine that most of them had a semi-sloping crown but the establishment of Ishiwata's and Tange's pre-built fork programs seem to have eliminated them or at least pushed them into obscurity by the 1980s.