Publisher Desc.  The plot of Sullivan's Operetta The Mikado tells the story of Nanki-Poo, son of the Mikado of Japan and the young girl Yum-yum. The Trio Three little maids from school is sung in the first act by Yum-Yum and her sisters Pitti-Sing and Peep-Bo when Yum-Yum first meets Nanki-Poo.