Mob Psycho 100 Reigen -The Miraculous Unknown Psychic- is a feature-length OVA produced by Studio BONES and released on March 18, 2018. It is a recap of the first season, from the beginning of the series to the 7th Division Arc, but instead told mainly from the perspective of Reigen, with edits and details added to the story that make him the main protagonist. The OVA also served as the announcement of Mob Psycho 100 II, the anime's second season.
Plot[]
Prologue[]
The story opens with Reigen watching a TV program called The Buzz List Principle in the Spirits and Such Consultation Office. The psychic Sophia Kirari advertises her recent book, which has already seen commercial success. Inspired, Reigen calls Mob into the office and tells him they are going to write a book about their experiences fighting evil spirits and the 7th Division of Claw. When asked about publishing costs, Reigen claims he'll start a crowdfunding campaign.
Chapter 1: As the Protector of Seasoning City[]
Reigen tells the stories of how he exorcised Ceiling Crasher and the Boss with his salt-based special techniques, not even calling Mob. He also details his jobs with several citizens of Seasoning City, whom he helped with other special techniques. However, Mob is confused, recalling that he was the one who defeated Ceiling Crasher. Reigen assures him that he will appear in the next chapter.
Chapter 2: As a Master Who Guides His Disciple[]
Reigen recaps how Mob approached him, and how he took him in as a disciple. Mob quickly came into his own as a psychic, exorcising the giant spirit in the Boss' tunnel and the Scent-Ghoul at the girls' academy. He also tells of Mob's encounter with Dimple and the (LOL) Cult, and the destructive battle between Mob and Teruki Hanazawa at Black Vinegar High School.
It's revealed that Mob has been writing this chapter at home, as Reigen allowed him to write his part however he wanted to. Ritsu reminds him not to overwork, inspiring Mob to write about Ritsu next. He explains his relationship with his brother, including their difference in psychic powers. He tells the story of how Ritsu awakened his own powers with Dimple and was subsequently kidnapped by the Claw esper Koyama.
Chapter 3: The One Who Fights Evil[]
The next day, Mob meets with Reigen to continue writing the book. In the story, Reigen explains that he chose to save Ritsu, infiltrating the 7th Division hideout alone. In a badly-edited sequence, Reigen's head pasted onto Teru's body defeats Terada outside the hideout. He also takes credit for defeating Koyama, Matsuo, Miyagawa, and Takeuchi, though he graciously lets Mob keep the credit for beating Tsuchiya, Mukai, and Muto. Mob questions this change, but Reigen assures him that all books dramatize their events to some extent.
Final Chapter: As a Member of the Masses[]
Back to the story, Mob is reunited with Ritsu and the team begins to leave, but they are stopped by the remaining 7th Division Scars. The rest of the fight plays out as in the anime, with Ritsu and Teruki fighting the Scars while Reigen urges Mob not to fight. Reigen is struck from behind by Sakurai, though he survives the attack and "unleashes his psychic powers" to beat the Scars into submission. When Ishiguro persists, another sequence plays where Reigen's head pasted on Sho's body defeats him. Reigen then summarizes that he saved Mob's brother and stopped Claw's plans of world domination.
Epilogue[]
Mob, now in the Telepathy Club and Body Improvement Club's shared room, finishes the book and gains applause from his peers. Ichi says she knows a good place to print copies, but Teru and Ritsu enter the room to fact-check the book before it's released. The Telepathy Club, Mezato, and Dimple agree to help. Upon reading, they are horrified by the book's constant inaccuracies.
Back at Spirits and Such, Reigen has received the first copy of the book and reads it in front of Mob. However, he is distraught when he discovers all of his embellishment is gone and that the book is entirely non-fiction. He complains that he isn't even the book's main character anymore. Mob explains the intervention of his peers, and Reigen tells him they'll have to rewrite the whole thing. However, after checking the crowdfunding page, Reigen learns they didn't collect enough money to get the book published anyways, reaching only 1% of their goal. Disappointed, Reigen takes Mob out for ramen.
At the ramen shop, Reigen reveals that he was the only one who donated to the crowdfund, believing 0% would look sketchy so he should start it off. Afterwards, Reigen heads to the bar Happy Trails and orders an extra sour drink. He wonders out loud when something good will happen; on cue, a TV turns on with an important announcement: Mob Psycho 100 II is on its way.