Residents of Japan will be vaguely aware of the long-nose impish figures known as Tengu, thinking of them as piquant figurines without deep religious significance. Tengu take many shapes in Japanese folklore, for instance as mischievous kidnappers of children or Pucks leading travelers astray.
Haruko Wakabayashi focuses on a grimmer aspect of the imp, as he appears in Buddhist thought, connected with evil forces such as the demon Mara who distracts monks from their spiritual path. She shows how Buddhists used Tengu images to "demonize" challengers of authority and to shore up their own institutional legitimacy.
If Tengu are really so wicked, it may become hard for us to look on them benignly any longer as cute ornaments. But perhaps what Buddhist monks see as evil is really only something mildly naughty. In any case the author is of the devil's party, locating the real "evil" in the repressive Buddhist establishment, though she does not develop this idea very much.