Act One

The show opens in a provincial German town in the late nineteenth century. Teenaged Wendla Bergman looks into a mirror, gently exploring her maturing body. She wonders about her changing feelings and wishes her mother would teach her what these changes mean ("Mama Who Bore Me"). Frau Bergman, Wendla's mother, enters and chastises her for wearing a childish dress – she must dress more properly because she is already in bloom. Wendla doesn't understand. Frau Bergman has good news: Wendla's sister has been visited by the stork and now has another baby girl. Wendla asks her mother to tell her where babies actually come from, as she knows the stork story is for children. Her mother tries to tell her but is too embarrassed to go into detail. Frustrated, Wendla and her friends lament their ignorance of these matters ("Mama Who Bore Me – Reprise").

At the boys' school, Herr Sonnenstich makes his pupils recite Latin. Mortiz Stiefel has fallen asleep in class, and Herr Sonnenstich embarrasses him by making him recite when he clearly doesn't know the text. His friend, Melchior Gabor, tries to come to his rescue by questioning the teacher's interpretation of the text. Herr Sonnenstich will have none of Melchior's outside-the-box thinking. In his mind, Melchior pushes back against the restrictive teachings of his elders ("All That's Known"). Moritz thanks Melchior and confesses the reason he hasn't been sleeping: he is troubled by mortifying dreams – he envisions a pair of legs in blue stockings. Melchior confirms that everyone in their class has similar dreams, including Georg Zirschnitz, dreaming about his piano teacher. The boys rock out, sharing their various fantasies ("The Bitch of Living").

After class, Melchior promises to enlighten Moritz about his dreams. Meanwhile, the Headmaster and one of the teachers worry that Moritz is polluting Melchior, their brightest student, by association. They take comfort in knowing that Mortiz will probably not pass to the upper grade. Later that afternoon, Wendla and a group of girls walk through the woods, discussing their secret crushes. They are all in love with Melchior. Everyone, girls and boys alike, is hung up on the new feelings that are taking them over ("My Junk").

At the Gabor house, Moritz tries to process the drawings that Melchior gave him that describe male and female relations. Melchior's mother interrupts them and, although she is surprised to see her son reading Faust, she trusts him to decide for himself what is good for him. Moritz is overcome with anxiety about what he has learned as the boys and girls yearn with anticipation ("Touch Me").

Melchior and Wendla discover each other in the woods. They sit together beneath an oak tree, secretly longing for each other ("The Word of Your Body").

Back at school, Moritz has snuck into the headmaster's office and discovers that he has passed his midterm exams. He is ecstatic. The teachers, on the other hand, are concerned that it will reflect badly on them if Mortiz advances to the next grade. Herr Knochenbruch reminds Fraulein Knuppeldick that he will be grading the final exams, and she is reassured that their school's reputation will be safe.

Walking home again, the girls discover that Martha's father beats her with a belt. They urge her to tell someone, but she is concerned that she will be thrown out of the house, like their friend, Ilse. The girls are troubled by the situation as Martha reveals to the audience the part of her father's abuse that she cannot tell her friends; she is joined by Ilse ("The Dark I Know Well").

Back in the woods, Melchior writes in his journal. Wendla finds him. She tells him about the situation with Martha and says that she cannot imagine ever being hit. She picks up a stick and asks him to beat her with it. At first, Melchior refuses, but then, after a moment of gently tapping her, he is overcome and hits her very hard and yells at her ("The Word of Your Body – Reprise 1").

Meanwhile, at Moritz's house, his father threatens him if he does not advance to the upper grade. Moritz writes a letter to Frau Gabor, asking for money so that he can escape to America because he has failed his exams and not been promoted. She refuses him the money, but offers to talk to his parents on his behalf. This is not enough, and Moritz experiences a nervous breakdown ("And Then There Were None"). He exits with a gun in hand.

Melchior is very disturbed by what has happened with Wendla in the woods ("The Mirror-Blue Night"). With his journal in her hand, she finds him in a hayloft and confesses to having read some of it. She apologizes to him for making him hit her, but he takes responsibility for what happened. They get close to each other, and he kisses her. As he starts taking it further, Wendla is hesitant but Melchior insists that they ought to be allowed to love and feel something. As he begins to touch her, she tells him to wait, but he reassures her that it is just him, and they come together ("I Believe").

Act Two

At church, Father Kaulbach sermonizes about children betraying their parents while, in the hayloft, Melchior asks Wendla if she is okay; she is lost in what just happened, but she thinks that she is okay ("The Guilty Ones").

Moritz stands alone by a river. He is at the end of his rope ("Don't Do Sadness"). Ilse stumbles upon him and reminds him of their time together as children, playing with Wendla and Melchior ("Blue Wind"). Moritz is distracted and upset; Ilse asks him to spend time with her, but he refuses – he has too much schoolwork ("Don't Do Sadness / Blue Wind"). She asks him to walk her home, but he refuses. She chastises him for abandoning her and leaves. He regrets not having gone with her, but then makes his decision and cocks the gun.

Later, at Moritz's funeral, Melchior indicts the adults who betrayed Moritz by pressuring him so much, while mourning the loss of his friend ("Left Behind"). At school, Melchior gets called to the headmaster's office. They have found his drawings. They blame Moritz's actions on the drawings and Melchior. They ask Melchior if he, in fact, did do the illustrations; he knows that he's stuck ("Totally Fucked").

In a vineyard at sunset, Hanschen and Ernst roll in the grass. Hanschen observes that there are three ways a man can go: let the status quo defeat him, like Moritz; rock the boat, like Melchior; or bide his time and let the system work for him, like Hanschen does. Ernst confesses his deep love for Hanschen as they make love ("The Word of Your Body – Reprise 2").

Melchior writes to Wendla, asking to return with her to their paradise. Simultaneously, Wendla sees a doctor who reveals to Frau Bergman that Wendla is pregnant. Wendla is shocked and she lashes out at her mother for not telling her everything. She gives her mother Melchior's letter. Melchior's parents discuss what to do about him. Frau Gabor believes it is too harsh to send him to a reformatory. However, when Herr Gabor shows her the letter that he wrote to Wendla, admitting that he knew what he was doing, she acquiesces ("Whispering").

At the reformatory, the other boys harass Melchior. They steal a letter that Wendla has written to him, and reveal to him that Wendla is pregnant. Meanwhile, Frau Bergman takes Wendla to a secret abortionist. Melchior escapes the reformatory and writes to Ilse, who shares the letter with the other girls. He plans to go to the graveyard at midnight to wait for her; the girls realize that he doesn't know what has happened to Wendla.

When Melchior gets to the cemetery, he finds Wendla's grave. He is bereft and contemplates suicide. The ghosts of Moritz and Wendla appear to comfort him and urge him forward into the world, holding on to the memory of what happened to his friends ("Those You've Known"). He promises never to let them go. Ilse then stands alone. She reflects on the events that have happened; she is joined by the rest of the cast as they look towards a time when all shall know the wonder of purple summer ("The Song of Purple Summer").