poor minstrel, Nanki-Poo, arrives and introduces himself ("A wand'ring minstrel I"). He inquires about his beloved, a schoolgirl called Yum-Yum, who is a ward of Ko-Ko (formerly a cheap tailor). One of the gentlemen, Pish-Tush, explains that when the Mikado decreed that flirting was a capital crime, the Titipu authorities frustrated the decree by appointing Ko-Ko, a prisoner condemned to death for flirting, to the post of Lord High Executioner ("Our great Mikado, virtuous man"). As Ko-Ko was the next prisoner scheduled to be decapitated, the town authorities reasoned that he could "not cut off another's head until he cut his own off", and since Ko-Ko was not likely to execute himself, no executions could take place. But all the town officials, except the haughty nobleman Pooh-Bah, proved too proud to serve under an ex-tailor and resigned. Pooh-Bah now holds all their posts and collects all their salaries. He informs Nanki-Poo that Yum-Yum is scheduled to marry Ko-Ko on the very day that he has returned ("Young man, despair"). Ko-Ko enters ("Behold the Lord High Executioner") and asserts himself by reading off a list of people "who would not be missed" if they were executed ("As some day it may happen"), such as people "who eat peppermint and puff it in your face". Yum-Yum appears with Ko-Ko's other two wards, Peep-Bo and Pitti-Sing ("Comes a train of little ladies", "Three little maids from school"). Pooh-Bah does not think that the girls have shown him enough respect ("So please you, sir"). Nanki-Poo arrives and informs Ko-Ko of his love for Yum-Yum. Ko-Ko sends him away, but Nanki-Poo manages to meet with his beloved and reveals his secret to Yum-Yum: he is the son and heir of the Mikado, but travels in disguise to avoid the amorous advances of Katisha, an elderly lady of his father's court. They lament that the law forbids them to flirt ("Were you not to Ko-Ko plighted"). Ko-Ko and Pooh-Bah receive news that the Mikado has just decreed that unless an execution is carried out in Titipu within a month, the town will be reduced to the rank of a village, which would bring "irretrievable ruin". Pooh-Bah and Pish-Tush point to Ko-Ko himself as the obvious choice for beheading, since he was already under sentence of death ("I am so proud"). But Ko-Ko argues that it would be "extremely difficult, not to say dangerous", for someone to