What a fantastic addition to your collection! These are great items. I love seeing signatures like this on the forum. 99% of autograph collecting tends to come from celebrities. And while I don't look down on anyone for wanting autographs from movie stars and musicians (I'm as guilty as anyone), it always puts things in a different perspective to see autographs from historical figures.
In the last season of Twin Peaks, David Lynch created a sequence exploring the Trinity bomb test, set to Krzysztof Penderecki's Threnody for the Victims of Hiroshima. It's one of the most unnerving things I've ever seen on film. Over the last 75 years, society has become comfortable with the idea of nuclear weaponry, because we've been lucky enough to have avoided it since Hiroshima and Nagasaki. It's easy to forget how utterly terrifying and evil it is that there are people today who hold that kind of destructive power in their hands. So it's important that people like Kiyoshi Kikkawa aren't forgotten.
So thanks so much for sharing these. That first signature in particular is remarkable.