Shibumi by Trevanian

A westerner raised in Japan, he survived the destruction of Hiroshima to emerge as the world's most artful lover and its most accomplished assassin. His greatest desire is to attain a state of effortless perfection . . . shibumi. But he is about to face his most sinister and corrupt enemy -- a supermonolith of espionage and monopoly bent on destroying
him. . . .

From the Paperback edition.

https://rapidgator.net/file/814e3471fed3852346ecdc3efe2d8f5d/

http://nitroflare.com/view/2D19D935278DA37/