As a seed-stage VC who has had the chance to interact with a number of Japanese entrepreneurs spinning businesses out of research at Harvard or MIT, I haven't found the conversations more superficial than with American entrepreneurs.

Maybe there's large sums of money at stake, polite and superficial conversation is a way of mitigating risk? I won't pretend to know the answer, but as a deep technologist I find the fundraising conversations with entrepreneurs deeply dissatisfying on average. And as a multi-time entrepreneur myself, I have definitely felt the same way sitting on the other side of the table.