The parents of a high school student who leaped to his death after an allegedly violent dressing down in class are suing the school.

The family is seeking ¥140 million in damages from the private high school in Ishikawa Prefecture, for the 15-year-old boy's death in October 2012, it was learned in a court session on Monday. The school is operated by the city's Inaoki Gakuen educational company.

The lawsuit, filed with the Kanazawa District Court, is directed at one of the teachers at the Seiryo High School in the city of Kanazawa. It alleges that the teacher's violent behavior directly led to the first-year student's death.

The lawsuit says the boy got caught using his cell phone during class. The teacher became violent and grabbed the student by the collar. The boy panicked and made his way to a balcony on the seventh floor and jumped off.

In a press conference following his death, the school quoted the teen as telling one of his friends earlier, "I'm sure I'll fail this test and (I'm thinking about) killing myself." The plaintiffs allege this shows the boy had been suffering emotional distress.

During Monday's first oral proceeding, the school pleaded not guilty, saying "there was no act of violence" on the part of the teacher. It said it would dispute the factors behind the tragedy.