This paper analyzed the impact of the earthquake, tsunami, and explosion-disaster at the Fukushima nuclear power plant in March 2011 on a small-medium cardboard manufacturer’s production and transportation systems. We first estimated the Cobb-Douglas production function to determine the change pre- and post-disaster using time-series monthly data from January 2010–December 2012 (35 months); we found few structural changes to the input ratio in the company’s production system. We then performed statistical analyses to investigate changes in the cargo flow originating at the firm and shipped to devastated/non-devastated destinations. The results indicated that the disaster affected cargo flow only to the coastal area devastated by the tsunami or contaminated by nuclear radioactivity. Since the demand for cardboard is a “derived demand” of agriculture and relatively light industries, this finding suggests that these industries were not unduly impacted by the disasters, and that the disaster’s effects may be overemphasized.