Shin-chan and his friends play the detective game and help Yoshinaga find her lost sandal that was stolen by a dog. Shin-chan eats a lot of snacks in the night and complains about pain in his stomach. So, Hiroshi and Misae take him to the hospital in an ambulance and admit him. The other patients give Shin-chan sweets as a gift on his farewell. Shin-chan eats the sweets and falls sick again.