In Japan before World War II, multiple pathways existed for the supply of secondary school teachers. Each pathway had distinct characteristics and played a complementary role. Among them, the temporary teacher training schools were the only route that functioned as a regulatory mechanism for balancing teacher supply and demand, as they enabled the systematic and expedited training of secondary school teachers. This study focuses on the role of these institutes in "supply-demand adjustment" and aims to clarify the characteristics of Japan' s secondary school teacher supply-demand adjustment policies before the war. Furthermore, it examines whether such temporary training institutions could serve as an effective measure to address the current shortage of secondary school teachers in Japan.