TOKYO -- A 50-year-old man who was arrested after allegedly fatally stabbing a colleague at a law firm in Tokyo's bustling Ikebukuro area July 1 reportedly told investigators that he held a grudge against the victim for some time.

At around 11:50 a.m., an emergency call was made saying a male employee had been stabbed by a man with a knife at Adire Legal Professional Corp. located on the 31st floor of the Sunshine 60 building in Tokyo's Toshima Ward.

Daiki Yoshino, 36, an employee of the law firm and resident of the capital's Toshima Ward, was stabbed in the neck and confirmed dead at a hospital. The Metropolitan Police Department (MPD) made an emergency arrest of his colleague, Reito Watanabe, a resident of Tokyo's Shinjuku Ward, on suspicion of attempted murder.

Watanabe is accused of attempting to murder Yoshino by stabbing him multiple times in the neck with a folding knife with a blade about 9 centimeters long at around 11:45 a.m. inside the office. He reportedly has admitted to the allegations and told investigators, "I held a grudge against Yoshino for some time and reached my limit. I stabbed him with a knife I brought from home because I wanted him to feel pain. I didn't care if he died." Police are now treating the case as murder and are investigating the background of the incident.

According to the MPD's Sugamo Police Station, Watanabe is believed to have stabbed Yoshino from behind while he was seated. The suspect then left on foot and turned himself in around noon at a police box near Ikebukuro Station's east exit, about 500 meters from the scene. Two additional knives were found in his backpack.

The law firm is known for handling many lawsuits related to the return of overpaid interest on loans. According to its website, it is headquartered in the Sunshine 60 building and has at least 235 lawyers at 65 offices nationwide. In 2017, it was suspended from business operations for two months by the Tokyo Bar Association for repeatedly advertising a free initial fee campaign for overpayment claims that was not true.

After the latest incident, the law firm released the following comment: "We sincerely pray for the repose of our deceased employee. We will fully cooperate with the investigation and promptly report the facts as they become clear."

(Japanese original by Yuka Asahina and Kosuke Yamamoto, Tokyo City News Department)