Quick Answer
Mob Psycho 100 Chapter 21 is part of the Big Cleanup Arc (Chapters 20 to 33), where Ritsu Kageyama’s longing for psychic power draws him toward the Awakening Lab while Mob keeps up his school life and his friendship with Telepathy Club president Tome Kurata.
Key Facts at a Glance
- Chapter 21 sits inside the Big Cleanup Arc, which runs from Chapter 20 to Chapter 33.
- The Awakening Lab is an organization that trains people hoping to awaken psychic abilities.
- Ritsu Kageyama has no psychic powers at this point and envies his older brother’s.
- Tome Kurata, president of the Telepathy Club, keeps pulling Mob into her search for espers.
- Previous chapter: Chapter 20. Next chapter: Chapter 22.
- Sources: Mob Psycho 100 Fandom Wiki and Wikipedia. Last checked October 18, 2026.
Mob Psycho 100 Chapter 21 Summary
Some chapters are about big fights. Mob Psycho 100 Chapter 21 sits in the middle of the Big Cleanup Arc, and it is about people, which is exactly why it works.
Mob has a new kind of problem: friends. Tome Kurata, the president of the Telepathy Club, keeps dragging him along in her search for real psychics, and Mob goes along with it in his usual deadpan way. She is chasing contact with the paranormal and, if she gets her way, with aliens. She is also the one person in the story who treats the supernatural as something to be excited about rather than afraid of, which makes her a lighter counterweight to everything else happening around Mob.
Underneath that lightness, the Ritsu thread keeps tightening. Ritsu is the brother who does everything right and still feels like he is coming second, because Mob has psychic powers and he does not. In this part of the arc his longing for those powers becomes hard to hide, and it leads him toward the Awakening Lab, an organization that trains people who hope to awaken psychic abilities. If you have ever wanted something badly enough to stop listening to your own warning signs, you already understand why he walks in.
Along the way Ritsu also crosses paths with Reigen, who treats him the way he treats everyone: with confidence and an invitation to tag along on a job. Ritsu turns him down and points out that he has no psychic powers like his older brother. It is a short exchange, but it tells you how Ritsu sees himself.
What makes this stretch sting is how little Mob knows. He is not oblivious in a dumb way. He is oblivious in the way people are about family: he assumes Ritsu is fine because Ritsu has always acted fine. The series loves this kind of dramatic irony, where the reader can see the collision coming and the characters cannot.
It also helps to read this chapter as a bridge. The first beats of the arc set the pieces on the board, and here the manga starts moving them toward each other. Tome’s cheerful hunt, Ritsu’s private frustration and the Lab’s quiet pull all run in parallel, and none of them touches the others yet.
Ready to read? Pick up from Chapter 20, continue with Chapter 22, or browse the full Mob Psycho 100 chapter list.
Mob psycho 100 Chapter 20 image 28
Mob psycho 100 Chapter 20 image 28
