The collection includes 19 lecture manuscripts prepared between the autumn of 1934 to the beginning of 1939. Surprisingly, Yukawa wrote many of his lecture manuscripts in a speaking tone. The manuscripts are written as if speaking to the audience right in front of him. Yukawa wrote the lecture manuscripts in his unique cursive writing style while paying utmost attention to logical reasoning. Yukawa must have presented each and every lecture with a mission to drive home the interesting worlds of quantum physics and modern physics and their importance to the students and colleagues in the Department of Physics as well as to specialized scholars and laymen.