The parents of a 17-year-old high school student who committed suicide last year said Monday they will file a damages suit against his classmates and teachers, arguing their son's death was caused by school bullying.

They will seek roughly ¥88 million in compensation in the suit, to be filed with the Kobe District Court as early as Dec. 4, as they hope to hold the Hyogo Prefecture high school liable, the boy's father said.

The boy killed himself on Sept. 2, 2012, at his home in Kawanishi. According to the parents' complaint, the reason was apparently because three of his classmates often bullied him in the months before his death by calling him "bug," putting dead moss on his seat and trying to make him eat an insect.

The school received information about the bullying from other students but failed to take appropriate measures, they said.

An independent panel set up by the prefectural board of education looked into the case and concluded in May that while the boy was bullied, it was not the cause of his suicide.