more (at source): Astronomically popular, "thumb novels" are much decried as trash for yahori ("slow learners"). But over the past few years this trashy subculture has stormed Japanese commercial book publishing. In 2007 – keitai shosetsu's annus mirabilis – half of the top 10 fiction bestsellers in the shrinking Japanese book market originated on cellphones.

Last autumn, a literary grandee joined in. Jakucho Setouchi, the Marguerite Duras of Japan, revealed herself as "Purple", the author of a keitai shosetsu about a teen's search for love entitled Tomorrow's Rainbow. Setouchi is also a celebrated 86-year-old Buddhist nun who wrote a contemporary update of The Tales of Genji, Japan's racy classic.