Many Japanese scholars remained at the university in the years immediately following World War II, giving Tsao the opportunity to audit Rokuro Kuwata's course on the history of East-West communications.
當時二戰結束不久，許多原任職台北帝大（即台大）的日籍學者仍繼續留任，曹永和也旁聽過著名學者桑田六郎的「東西交通史」。