Misae unknits Hiroshi's old sweater to make a new one for him but ends up knitting a sweater for Shiro with the same wool. Hiroshi is on his way to work when he encounters Shin-chan, who is playing detective and has trailed him to the train station. Shin-chan pesters the passengers in the train with his mischief and his talks. Hiroshi brings Shin-chan to his office. Arriving at the office, Hiroshi tells Shin-chan to wait patiently in the lobby till his mother can come and get him. Shin-chan escapes from the recreational room and meets the president of the company and has fun with him.