Okay, not so mysterious for most of us here. This is an older article but it doesn't appear to have been posted before. More of a fluff piece, but a fun, quick read about YKK.
"Yoshida also preached a management principle he termed “The Cycle of Goodness.” It holds that “no one prospers unless he renders benefit to others.” In practice, this boiled down to Yoshida striving to produce ever-higher quality with ever-lower costs. It seems intuitive, but it’s far from easy to do."
Why YKK? – Slate
[edited to fix link]