John Woo is a carrier pigeon used by Mr. Kim to send messages and assignments to the Paper Sisters. The sisters name him after the famous Chinese film director, one of whose trademarks is the use of doves to highlight dramatic moments. The pigeon demands respect and pecks Maggie Mui when she forgets to call him "-san" ("Mr."). While originally serving Dokusensha, Mr. Woo remains a "friend" to the Three Sisters throughout the series.