(defun my-org-table--shrink-field (old-fun width align start end contents)
  (if (or (= start end)
          (org-table--shrunk-field)
          (= 0 width)
          (eq contents 'hline)
          (equal contents ""))
      ;; 関係ないところは従来のコードを呼び出す。
      (funcall old-fun width align start end contents)

    (let* ((lead (org-with-point-at start (skip-chars-forward " ")))
           (trail (org-with-point-at end (abs (skip-chars-backward " "))))
           (contents-width (org-string-width
                            (buffer-substring (+ start lead) (- end trail)))))
      (cond
       ((<= width contents-width)
        (let ((pre
               (and (> lead 0)
                    (org-table--make-shrinking-overlay
                     start (+ start lead) "" contents t)))
              (post
               ;; widthを超えない最後の位置を分割点とする。

               ;; Find cut location so that WIDTH characters are
               ;; visible using dichotomy.
               (let* ((begin (+ start lead))
                      (lower begin)
                      (upper (1+ (1- end))) ;;+
                      ;; Compensate the absence of leading space,
                      ;; thus preserving alignment.
                      (width (if (= lead 0) (1+ width) width))
                      (divpos
                       (progn
                         (while (> upper lower)
                           (let ((mean (ash (+ lower upper) -1)))
                             (if (< width (org-string-width (buffer-substring begin mean)))
                                 (setq upper mean)
                               (setq lower (1+ mean)))))
                         (1- upper)))
                      ;; 分割点までの幅を計算する。
                      (str-w (org-string-width (buffer-substring begin divpos))))
                 (org-table--make-shrinking-overlay
                  divpos
                  end
                  ;; 足りない分を空白で埋める。
                  (make-string (- width str-w) ? )
                  contents))))
          (if pre (list pre post) (list post))))
       (t
        ;; 関係ないところは従来のコードを呼び出す。
        (funcall old-fun width align start end contents))))))

(advice-add #'org-table--shrink-field
            :around #'my-org-table--shrink-field)

;; (advice-remove #'org-table--shrink-field
;;                #'my-org-table--shrink-field)