Okay here me out on this one. I am certain there are no Sho and Reigen interactions in the manga (just a hunch), but I really wanted these two to interact, so… I created an AU that’s still in the works.
Here are a few things about the AU:
After his wife left, Toichiro was left to raise Sho. However, it didn’t last long because he abandoned him. His reason: Sho wasn’t “fit” to be his son. (Was Sho considered “weak” to him?)
Sho has been alone and homeless for… either a few months or a year, but he managed to survive. He also honed on his psychic powers and got better control of it.
Sho’s life was about to change when he met Reigen, who was still in college that time.
Reigen was heading home until he saw someone hanging around in the alley. When he noticed it was a kid, he just felt his heart drop. (“How long has he been living on the streets alone?” “Where are his parents?” “Was he abandoned?” “How can he manage to survive?”)
Reigen was really concerned about Sho’s condition, so he persuaded the boy to let him stay in his apartment.
Sho was pretty stubborn though, so he refused and left. Reigen was also pretty stubborn, so whenever he saw the same boy, he kept persuading him until Sho finally gave in. (Roughly… a week or two)
Sho has been living with Reigen quite a while. There were times that he wanted to leave, but he didn’t do it.
Despite being swamped with assignments or studying for his exams, Reigen managed to take the time to teach Sho during his breaks.
There was one time Sho showed his psychic powers to Reigen, and Reigen was really amazed. (Reigen’s interest in the supernatural)
Reigen decided to teach him how to use his powers for good
Sho was skeptical, but just went with it
… Okay that was just a build up how Reigen and Sho met, so here’s the fun part:
One time, during Reigen’s Summer break, a few people mistook them as father and son which surprised them. They just went with it.
Sho accidentally called Reigen his dad after that little mishap.
Reigen didn’t mind in the slightest (“It sounds a little better than ‘Reigen-san’ right?”)