Went to the above mentioned lecture at Meiji University, presented by Leif Høgfeldt Hansen, Associate Professor in Architectural History at Aarhus School of Architecture, Denmark.
What did I learn? That the "missing link" between Japan, F.L. Wright and Aalto may be Antonin Raymond and his published works about Japan. For sure, in Europe Bruno Taut and others are more well known to have strongly influenced the picture about Japan. But Raymond? Did he publish? Obviously at least one VERY nice book about his own "Architectural Details" in 1938 with only 1000 copies, pretty rare by now. Added some references in the "further readings" section. That Aalto and Raymond might have met is quite possible, as the following fact illustrates. Both attended a symposium in New York in May 1939, Aalto as speaker, Raymond in the audience, see here.