Politicians are turning author on a wide range of subjects, including political exposes and the frank disclosure of a broken marriage.
It is generally considered standard practice for potential prime ministers to publish books outlining their plans for a new administration.
The late Prime Minister Kakuei Tanaka published a best-seller, "Nippon Retto Kaizo Ron" ("On Rebuilding the Japanese Archipelago"), before his successful bid to succeed Eisaku Sato. The book sketched his plans to relocate industrial facilities outside metropolitan areas, among other things. It is said to have sold more than 900,000 copies.