The Tokyo District Court has sentenced a former junior high school principal to nine years in prison for sexually assaulting and injuring a female student 14 years ago.

The 57-year-old defendant, Kitamura Hisayoshi, was the principal of a junior high school in Tokyo's Nerima ward when he was arrested last year. He has been charged with sexually assaulting and injuring one of the victims, a then 14-year-old female student at school, where he worked as a teacher.

He was also charged with possessing video footage of the victim he assaulted in his principal's office, as well as video of a sexual act with another student.

He had pleaded not guilty to the sexual assault charge, saying he believed the girls had consented to his actions.

Presiding Judge Hosoya Yasunobu brushed aside the defendant's claims, saying footage shows the girls crying, and it is evident they had not consented.

He noted that the defendant took advantage of his position of authority over the students and that his actions escalated after he tricked them by saying he was going to massage them.

He said the defendant habitually engaged in heinous behavior and it cannot be overlooked that the abuse took place on the school premises, a place where students should be protected.

He added the victims spent the rest of their junior high school days, unable to share their torment with anybody, and that their psychological suffering has been serious.

Prosecutors sought a prison term of 10 years.