Hiroto Oyama frequently dreams about his mother floating on the surface of water and his father standing on the gallows.
"I wake up by my own shouting voice," the 24-year-old Oyama said.
His father, Kiyotaka Oyama, 51, was convicted of killing his wife (Hiroto Oyama's mother) and his own foster father, and is now waiting to be hanged at the Hiroshima Detention House after his death sentence was finalized in June 2011.