TOKYO - Tetsuya Yamagami, the man who fatally shot former Japanese Prime Minister Shinzo Abe in 2022, filed an appeal on Wednesday against his life sentence.

The Nara District Court on Jan 21 handed down a life sentence to Yamagami, 45, who was convicted of murder and other charges for shooting Abe with a homemade gun in July 2022 while the former leader was delivering a campaign speech on a street in Nara.

The ruling rejected the defense counsel's argument that his unfavorable upbringing should be considered in determining his sentence.

READ MORE: Shooter of former Japan PM Abe pleads guilty in court

Masaaki Furukawa, one of Yamagami's lawyers, said the decision to appeal was made after consultations with the defendant to seek a review and possible correction of the initial ruling, the Asahi Shimbun reported.

Yamagami had earlier admitted to murdering Abe during his trial at the Nara District Court, saying that he committed the crime due to a grudge he held against the Unification Church because his family suffered financial ruin due to his mother's large donations to the religious group, which he believed had close ties to Abe and other Japanese politicians.

Yamagami's defense had called for a prison term of no more than 20 years, arguing that he was a victim of a religious group's harm and that his "tragic" upbringing motivated him to kill Abe.

READ MORE: Japanese police file new raps against Abe murder suspect

The court, however, maintained that while his upbringing involved significant hardship, it did not justify a substantial reduction in sentence.