Yamane was in the same elementary class as kenji and the crew. He joined Fukube's gang of friends because of his strange obsession with Friend. He later stayed in Fukube's inner circle and worked with Endou Kiriko as a researcher to discover the virus which killed 150000 people worldwide in 2000. He was also the man who developed the evolved version of the virus, which had killed 3 billion people in 2015. Feeling guilty for his actions after being visited by Kiriko, he decided to kill Fukube at the science room of their elementary school. He was shot immediately after by the friend police and died.