The Mikado, also known as The Town of Titipu, is Gilbert and Sullivan’s most popular operetta. The libretto was written Sir William Schwenck Gilbert, and the music was composed Sir Arthur Seymour Sullivan. Following Princess Ida, or Castle Adamant, The Mikado was their ninth operetta together. On 14 March 1885, The Mikado made its London debut at Richard D’Oyly Carte’s Savoy Theatre.
Nanki-Poo, the son of Japan’s ruler, the Mikado, had met Yum-Yum the previous year and the two had fallen in love. Because she was engaged to her guardian, Ko-Ko, a tailor, their love was thwarted, and Nanki-Poo returned to court, where his father threatened him with death if he did not marry the elderly and unattractive Katisha. Faced with this, Nanki-Poo has fled the courtroom and is now wandering the countryside as a wandering minstrel.
Nanki-Poo returns to Titipu after learning that Ko-Ko has been sentenced to death for flirting under the Mikado’s draconian law. Here, he learns that Ko-Ko has been pardoned but promoted to Lord High Executioner because, according to logic, he couldn’t cut off anyone else’s head until he’d cut off his own, ensuring the continued life of those who flirt and circumventing the problematic law.
Ko-Ko makes his first appearance as Lord High Executioner, revealing the list of potential victims he’s been compiling. Yum-Yum and her classmates arrive, and Nanki-Poo confesses his feelings for Yum-Yum to Ko-Ko, who accepts it gracefully. Nanki-Poo reveals his identity to Yum-Yum when he has the opportunity for a private conversation. When Ko-Ko enters, they flee unnoticed, and he is soon interrupted a letter from the Mikado demanding that he behead someone within a month or lose his rank and have Titipu demoted to a village.
Ko-Ko rejects the idea that he cut off his own head because he is already on death row, and his attempt to appoint one of his advisers to the position of Lord High Substitute, who would be executed in his place, backfires. Nanki-Poo, distraught at the prospect of not being able to be with Ko-Ko, enters with a rope in hand, intending to commit suicide. Nanki-Poo may be able to assist Ko-Ko agreeing to be beheaded instead at the end of the one-month grace period. Nanki-Poo agrees on the condition that he be permitted to marry Yum-Yum in the interim, and the two come to an agreement.
Katisha walks in and recognizes Nanki-Poo, but she is forbidden from revealing his true identity, so she flees to seek vengeance. Yum-Yum is torn between joy and sorrow as she prepares to marry her beloved. The news from Ko-Ko that when a man is beheaded, his wife is forced to be buried alive does not help her heart. Yum-Yum is unable to bear this and refuses to marry Nanki-Poo under these circumstances. Nanki-Poo, on the other hand, declares that he can’t live without Yum-Yum and returns to his suicide plan, which greatly irritates Ko-Ko.
The Mikado’s arrival is announced, and Ko-Ko fears he’ll be checking to see if an execution has been carried out. Nanki-Poo offers to be beheaded, but Ko-Ko has never killed an insect and is unable to carry out the request. Instead, he writes an affidavit stating that Nanki-Poo was executed, and Nanki-Poo and Yum-Yum marry. When the Mikado and Katisha arrive, Ko-Ko is delighted to inform him that the execution has taken place and hands him the affidavit. Uninterested, the Mikado inquires about his son, Nanki-Poo, who has been wandering around Titipu. He is told that Nanki-Poo has gone abroad, but Katisha deduces from the affidavit that he was murdered, because everyone in the vicinity is sentenced to the appropriate punishment for murdering the heir apparent.
Nanki-Poo is still afraid of being forced to marry Katisha, so Ko-Ko tries to persuade him to meet his father. To avoid this, he insists that Ko-Ko marry Katisha because it is the only way to ensure his happiness, which will encourage him to reappear and save Ko-life. Ko’s Ko-Ko persuades Katisha, Nanki-Poo reappears at the last moment, everyone is forgiven, and Nanki-Poo and Yum-Yum marry.