The Reds schemer was disappointed with his own performance in the 2-1 loss to Ivory Coast at the weekend but remains hopeful his country can progress from a group that also includes Colombia.
"We have to win," said Kagawa. "That's all I can say. We have prepared for it over the past several days. All I can say is we will win. We need to achieve the result."
The 25-year-old insists the players can pick themselves up after the disappointing defeat in Recife.
"We just finished one match," he stressed. "I would ask: 'What have we been doing for the last four years?' if we get discouraged already [after only one game]. I will shift my mind and do my best on Thursday."