Agent "J" (played by Wen Zhang) was shot in the head while performing an A-level mission, causing damage to the hypothalamus in his skull. During the period of recuperation, J gradually became a fat man weighing 300 pounds and suffered from severe narcolepsy, but J still believed that he was an ace agent. Finally, J received another mission and went to Japan alone to retrieve confidential documents. After obtaining the documents, J opened the documents without authorization and decided to continue to complete the mission hidden in them for the organization, but unexpectedly fainted in the izakaya. J, who woke up in the hospital, met the security guard Hao Yingjun (played by Bao Beier). Hao Yingjun resolutely joined the mission to prove that he was not a waste who had accomplished nothing. In the process of carrying out the mission, this temporary partner experienced one ridiculous and dangerous crisis after another...