Satoru Fujinuma

the teacher is the killer, just saying

History
As a child, Satoru is an ordinary child who spent his life hanging out with his friends casually. He's seen frequently with a grownup nicknamed Yuuki whom he looked up as an exemplar. He didn't involved himself yet into Kayo and the other 2 victims as he is just an innocent bystander which leading those 3 victims to their demise. In the criminal case, he desperately convinced his mother to protect Yuuki from being suspected as the serial murder and kidnappings but fail. All of these resulted in his current self which is a mangaka author and part-timer as a fast-food delivery boy.

2nd Leap Arc
At 7 p.m. on March 14, 1988, Satoru was transported to a hospital in the city. He spent a month there in an intensive care unit on a respirator, and was later moved to a general ward after becoming stabilized. Though the hospital recommended that he be taken off life support, his mother firmly rejected it and kept him on it. In July of 1989, he was transported to a hospital in Chiba. His mother moved to an apartment into an apartment and began home care. Nine years passed and in 2001 he suddenly started breathing on his own and his brain recovered up to a sleep state, but he didn't wake up. After waking up, he has no memory of what has happened to him or the events leading up to his coma.