Nanki-Poo, scorning the delights of his father, becomes a wandering minstrel because of his love for Yum-Yum. In the town of Titipu the laws of the Mikado seem, perhaps unnecessarily strict and when he expects ro see some fruit of his legislation, Ko-Ko bribes the disguised Nanki-Poo to take the principal part in an execution after a month's wedded life with Yum-Yum. The Mikado arrives to see that his orders are carried out and finds that the victim is his only son. Thanks to typical Gilbertian gymnastics, the Mikado, Nanki-Poo and even Ko-Ko are satisfied with the odious Katisha.