A jilted bride sues for breach of promise of marriage: the Defendant has found a new love. The judge and jury are much taken with the Plaintiff, while the ladies in the Public Gallery seem enamored of the Defendant. The Defendant claims that any damages must be small since he is such a "very bad lot" that the Plaintiff couldn't endure him for even a day! He offers to "marry this lady today and marry the other tomorrow." The judge ponders this nice dilemma and makes an imaginative ruling to settle the case happily.

HMS Pinafore’s gentle satire builds upon the theme of Love between members of different social classes. The gentlemanly Captain of the Pinafore, who claims that he would never swear at his crew, does not know that his daughter has fallen in love with a common sailor serving on her father's ship. Meanwhile, the Captain has arranged for her to marry the First Lord of the Admiralty, Sir Joseph Porter. Sir Joseph himself has risen from humble beginnings to gain his office by political acumen, despite having never gone to sea! And the Captain himself fancies a poor bumboat woman. Fear not: it all works out in the end.