Hankei was published as a limited edition of 2,500 copies and as in this example, some of them were bound with a white cover to be decorated by Munakata as a special-bound edition (as in this lot). For other special-bound examples, see Kodansha, Munakata Shiko Zenshu vol.1 (Tokyo, 1977), pl. 729 - 736.
The title is based on Munakata's essential idea that the 'board', or woodblock [han] is full of energy [kei] to be released by the carver. According to the postscript of the book, although it was published in midst of a difficult time for Japan during World War II, the monochrome prints had been newly executed for the book with Munakata's desperate pursuit of Hanga no Michi [Road of the Woodcut].
For a similar example in the British Museum see http://www.britishmuseum.org/research/collection_online/search.aspx, registration number 1989,0314,0.56.1-3