Krusty the Clown begins the episode performing on his show but quickly realizes he is no longer getting laughs from the audience. When he looks out, he sees that the audience is composed entirely of old people, not children. He asks the network executives why this is, and they explain that kids no longer watch his show, so the network fills the audience with elderly people who are lost in the mall. Krusty is dismayed by this and discusses the decline of clown popularity with other clowns at Mussel & Flanks. Little Debbie Dimples suggests opening a school to train children to become clowns, and Krusty becomes excited by the prospect of earning money from tuition fees. Before leaving, Dimples tries to tell Krusty the most important part of comedy but forgets it.

Krusty goes to the Town Hall to meet with Mayor Quimby and Superintendent Chalmers to propose opening a clown school. Chalmers is initially skeptical but eventually agrees. An advertisement is broadcast for the Herschel Krustofsky School for the Clowning Arts. Bart sees the ad and wants to join the school. Homer takes Bart to Krusty to enroll him. Krusty doubts Bart's academic abilities but agrees to accept him when Homer points out that other "loser" kids will follow Bart to the school. Rainier Wolfcastle also brings his son Dieter to enroll.

Bart quickly adapts to clown school and excels in his studies. The school teaches not only clowning skills but also academic subjects, including complex topics like geometric trajectories and even some Latin. Bart leads the clown school team in a competition against Springfield Elementary, which is led by Lisa. Bart's team wins, and Marge thanks Krusty for seemingly performing a miracle with Bart.

Krusty's success attracts the attention of Fat Tony, the Springfield mob boss, who approaches Krusty demanding a cut of the school's profits, citing the benefits of the rising tuition fees. Feeling threatened, Krusty reluctantly hands over control of the school to Fat Tony. Under mob control, the school quickly deteriorates, becoming a horrible place for the students.

Seeing the school's decline, Krusty decides to take action despite the risks. He goes to the police and asks for help. Chief Wiggum suggests that Krusty wear a wire hidden in his squirting lapel flower to gather evidence against Fat Tony. Krusty agrees, but the mob soon discovers the wire. Krusty is caught and in danger, but the students, who have grown to love him as their principal, arrive just in time to rescue him.

After the rescue, Fat Tony and his gang burn down the clown school to collect insurance money. A firetruck full of clown firefighters arrives but is unable to save the building. Krusty feels like a failure, but Bart reassures him that he made a positive difference in the lives of many kids. With the school gone, Krusty is happy again and regains the attention of the children, restoring his place as a beloved clown.

At the end of "Clown v. Board of Education," Krusty's clown school is taken over by the mafia, led by Fat Tony, who forces himself into the business. Krusty goes undercover for the police, wearing a wire to expose the mob's involvement. The mob quickly realizes the wire, but Krusty is saved by the loyalty of the kids who love him as their principal. Despite this, Fat Tony burns down the clown school for insurance money, and the clown firefighters fail to save it. The episode closes with Krusty hearing Bart ask him out for nachos, mishearing it as "naches," symbolizing a moment of parental pride.

Expanded narrative of the ending scene by scene:

The climax unfolds as Fat Tony, the Springfield mob boss, inserts himself as a partner in Krusty's successful clown school, exploiting the education racket since other mafia scams have dried up or lost appeal. Krusty, feeling trapped, contacts the police and agrees to wear a wire hidden in his squirting lapel flower to gather evidence against the mob.

During a tense scene at the school, the mobsters quickly detect the wire on Krusty, putting him in immediate danger. However, the children enrolled in the clown school rally around Krusty, showing their affection and support for him as the principal they genuinely like and respect. This collective loyalty helps protect Krusty from the mob's retaliation.

Despite Krusty's narrow escape, Fat Tony retaliates by setting fire to the clown school to claim insurance money. A firetruck staffed by clown firefighters arrives but is unable to save the building, resulting in the destruction of the school.

In the final moments, Krusty shares a quiet, tender interaction with Bart. Bart invites Krusty to go out for nachos, but Krusty mishears the invitation as "naches," a Yiddish word meaning parental pride. This mishearing creates a bittersweet moment, symbolizing Krusty's hope for approval and connection with his son, even as his school burns down.

Regarding the fate of the main characters at the end:

• Krusty: Though his clown school is destroyed, he survives the mafia threat thanks to the children's support and ends on a hopeful note with Bart.
• Bart: Continues to be engaged and enthusiastic about clowning, showing growth and enjoyment in the school before its destruction.
• Fat Tony: Successfully extorts the clown school, burns it down for insurance money, and escapes without immediate consequence.
• The children: They remain loyal to Krusty, showing their affection and support, but lose their school due to the fire.

This ending highlights the conflict between Krusty's desire to revive clowning and the corrupting influence of the mafia, while also emphasizing the bond between Krusty and the children who believe in him.

The Simpsons Season 34, Episode 21 titled "Clown v. Board of Education" does not have a specifically noted post-credit scene in the available detailed episode summaries or reviews. The sources describe the episode's main plot about Krusty opening a clown school and dealing with mafia involvement, but none mention a post-credit scene or extra content after the credits roll.

The YouTube video of the episode's ending credits also does not indicate any post-credit scene; it simply shows the credits themselves without additional scenes afterward.

Therefore, based on the information from episode summaries, reviews, and the credits video, there is no post-credit scene in this episode.

Krusty loses his audience because children are no longer watching his show, being distracted by social media, so the network fills the audience with old people who are lost in the mall.

At a meeting of clowns lamenting their declining popularity, Little Debbie Dimples suggests opening a school to train children to become clowns. Krusty is motivated primarily by the potential to make money from tuition fees.

Bart is interested in joining the clowning school after seeing an advertisement, and because of his experience as a class clown, he is immediately accepted. He performs well, leading the school to win a competition against Springfield Elementary.

Fat Tony forces himself into Krusty's clowning school business, taking control due to the lucrative tuition fees. His involvement leads to the school's decline, and eventually, he burns down the school to collect insurance money.

Krusty goes to the police and agrees to wear a wire to help catch the mobsters. However, the plan fails when the mob discovers the wire, and Krusty is caught. The students then come to his rescue, but ultimately the school is burned down for insurance money.

The Simpsons Season 34, Episode 21 "Clown v. Board of Education" is rated TV-PG, indicating it is generally suitable for a family audience but may contain some material parents might find inappropriate for younger children. The episode features typical Simpsons humor with satire and light comedy centered around Krusty opening a clown school.

Potentially objectionable or upsetting aspects for children or sensitive viewers include:

• Mild cartoon violence or slapstick typical of The Simpsons, such as pranks or physical comedy involving clowns.
• Some thematic elements involving school and authority figures, which might include mild conflict or tension.
• Possible references or jokes about social media and modern childhood distractions, which are handled humorously but could include sarcastic or critical tones.
• No reports of strong language, graphic violence, or adult themes in this episode have been noted in reviews or ratings.

Overall, the episode maintains the show's usual comedic style without significant content warnings beyond the standard TV-PG level. Sensitive viewers or very young children might want parental guidance due to the typical satirical and slapstick humor.