Self-Proclaimed Psychic - Reigen Arataka is the first chapter of the Mob Psycho 100 manga series.
Arataka Reigen is introduced as he accepts a case from his client, Hanako. She is guided through the exorcism courses that he offers. She is convinced of the validity of the courses and the deals that Reigen is offering to her. However, her lover, Taro, appears and claims that the deal and the courses are fishy. Reigen immediately denies the claim, saying that Hanako's face will return to normal after the course. Taro retorts, exclaiming that there is nothing wrong with her face.
At this point, it is revealed that Hanako has been having nightmares that involve a ghost. Walking outside with Reigen and Taro, Hanako says that they are at the building where the ghost is located, not indicating to which specific building, out of the many nearby, she was referring. Reigen claims he senses a dreadful aura from the nearby broken-down building. However, it turns out the building he sensed the aura from was not the building she meant. Reigen flusters, before indicating to a nearby man, claiming the man to be an evil spirit, the "Cleft Chin Monster".
Then, they go into the building. Hanako states a rumor that a man died in the building after hitting his head on the ceiling after seeing a cockroach. This immediately frightens Reigen, who is shown to be afraid of cockroaches. Then, a ghost, Ceiling Crasher, appears, with Hanako identifying it as the ghost that was haunting her. Reigen preforms his special move "Salt Splash", with the ghost brushing the salt aside. Reigen decides to call his mentor, Mob, who is revealed to be the main protagonist of the story. Mob arrives and easily exorcises the ghost, complaining to his master about calling him out to the middle of nowhere.
Reigen thanks Mob, with Mob questioning Reigen's apparent psychic abilities. Reigen claims that he could easily exorcise such a weak ghost with his great powers. He states he only called Mob out to the building so that Mob could exorcise the weak ghosts. Mob continues to question him, but Reigen claims that Mob just needs more training and teachings. Reigen says that he is teaching Mob how to use his powers to Mob's benefit. It's just a bonus that it helps the business that Reigen runs. Mob's explosion meter is first shown, showing the number 22%.
As a end-chapter, Taro is revealed to be considering that something is wrong with Hanako's face, as Reigen had suggested earlier.
- "Well we treat 'spirits' here as something like CO2." - Arataka Reigen
- "There's nothing wrong with her face!" - Taro
- "I also felt a really powerful aura gushing from it but it was from a different ghost!! Well, my bad." - Arataka Reigen
- "Are you a freaking elementary schooler!" - Taro
- "They say that long ago, in this area, a man was startled by a cockroach and when he jumped he stuck his head in the ceiling and died." - Hanako
- "With my great curse I'll put you all through the ceiling too!!" - Ceiling Crasher
- "It's the same head-butting person from my dreams!!!!" - Hanako
- "Well, maybe there's something wrong with her face" - Taro