Shigehisa is the teenage son of Kaede Akamatsu and Ibuki Mioda. Though his parents were never a couple, they co-parent well and never have bad things to say about each other, especially not in front of their son. He grew up relatively normally, though things were a bit odd having Ibuki as a parent. His being accepted into Hope's Peak was really no surprise.

Being forced into a killing game, on the other hand, was certainly a surprise.