anchor.diff:           ((:ha :hi :fu :he :ho)
             (geminate number-kana)
             (rendaku counter-kana :handakuten t))))
  -    (0 (unless (zerop (mod n 100))
  -         (case head
  +    (10 (case head
              ((:ka :ki :ku :ke :ko
                :sa :shi :su :se :so
                :ta :chi :tsu :te :to
  
positive.code: 
  (defmethod root-p ((obj counter-text)) t)
  
  (defmethod counter-join ((obj counter-text) n number-kana counter-kana
                           &aux (digit (mod n 10))
                             (head (gethash (char counter-kana 0) *char-class-hash*))
                             (digit-opts (assoc digit (digit-opts obj))))
    (when digit-opts
  
negative.code:             (geminate number-kana))
             ((:ha :hi :fu :he :ho)
              (geminate number-kana)
              (rendaku counter-kana :handakuten t))))
      (100 (case head
           ((:ka :ki :ku :ke :ko)
            (geminate number-kana))
           ((:ha :hi :fu :he :ho
             :pa :pi :pu :pe :po)
            (geminate number-kana)
            (rendaku counter-kana :handakuten t))))
      (1000 (case head
              ((:ha :hi :fu :he :ho)
               (rendaku counter-kana :handakuten t))))
      (10000 (case head
               ((:ha :hi :fu :he :ho)
                (rendaku counter-kana :handakuten t))))
      )
    (call-next-method))
  
  (defclass number-text (counter-text)
  