In his dorm room, graduating Jack Chesney is excitedly talking with his butler, Brassett, making sure that luncheon will be ready for later that afternoon.
He is so excited because his roommate, Charley Wykeham, has gone to the train station to meet his aunt, Donna Lucia D'Alvadorez, who is coming in from Brazil for a visit.
Having Charley's aunt there as chaperone will make it quite easy for their two girl friends, Kitty Verdun and Amy Spettigue, to come for a visit.
The girls arrive early, and just as expected decide they must leave – not seeing Charley's Aunt Donna Lucia.
Actually, they are more worried about being caught by their guardian, Mr. Spettigue, (Amy's uncle) who keeps a tight rein on the girls.
While Charley is doing this, Jack's father, Sir Francis Chesney, makes a surprise visit and informs his son that they are actually penniless.
After Jack's father leaves, Charley re-enters in costume rehearsing his lines for the school play.
The young ladies unexpectedly appear again assuming that a chaperone is there, and in a fit of desperation, Jack suggests that Charley pose as his aunt – anyway he's wearing the costume right now.
Sir Francis then enters the scene and escorts Charley to lunch all ready to woo a rich woman into marriage.
He is quite angry until he learns that this "woman/chaperone" who dismissed him only a few moments earlier is actually the wealthy Donna Lucia D'Alvadorez from Brazil – "where the nuts come from."
("The New Ashmolean Marching Society and Students' Conservatory Band") In a garden, Charley is returning from having just entertained both men.
Charley is ready to change back into his regular clothes and go and find Amy who must be wondering where he is.
Jack is still frantic and begs Charley to continue for a short while longer so he can talk with Kitty.
He apologizes for his absence, and rushes to talk to Amy about their future together before her uncle returns and whisks her away.
("Make A Miracle") Mr. Spettigue enters to find Amy with Charley and tells her to collect her things.
Sir Francis and the real Donna Lucia (still posing as Beverly Smythe) enter and unexpectedly join them for tea.
During a madcap tea party, Donna Lucia presses Charley for information about his/her life in Brazil.
A song and ballet sequence (seen through Charley's eyes) revealing just how Donna Lucia and her rich husband met and lived together ends the first act.
She also tells him that her uncle is ready to sign a wedding consent form, but Donna Lucia must meet him to get the document.
The ladies eventually all leave and Charley is left alone to talk with Mr. Spettigue who comes to play with his new love.
Charley fights off Mr. Spettigue's forced advances and finally demands that he be given the letter of consent that has been promised all along.
Strolling down a garden path Donna Lucia asks Sir Francis if it isn't strange that they have never seen Charley and his aunt together at the same time.
In fact, everyone is dancing the night away in love ("Red Rose Cotillion") Charley even makes an appearance as himself to keep poor little Amy happy and content.
Mr. Spettigue finally appears and announces the engagement of Kitty and Amy to Jack and Charley.
The real Donna Lucia finally steps forward and says that indeed the letter of consent was addressed to her and is a legal document – and she puts her blessing on the wedding.
The cast featured Ray Bolger as Charley Wykeham, Allyn McLerie as Amy Spettigue, Byron Palmer as Jack Chesney, Doretta Morrow as Kitty Verdun, Paul England as Sir Francis Chesney, and Horace Cooper as Mr Spettigue.
The cast featured Norman Wisdom as Charley Wykeham, Pip Hinton as Amy Spettigue, Terence Cooper as Jack Chesney, Pamela Gale as Kitty Verdun, Jerry Desmonde as Sir Francis Chesney, and Felix Felton as Mr Spettigue.
series from March 17–20, 2011, featuring Rebecca Luker and Howard McGillin, and Rob McClure as Charley.
The film's cast starred Ray Bolger, Allyn Ann McLerie and Horace Cooper repeating their stage roles, and Robert Shackleton as Jack Chesney, Mary Germaine as Kitty Verdun, and Howard Marion-Crawford as Sir Francis Chesney.