For many employees, a year-end bonus is a reward for hard work. For one Tokyo sales manager, a reduced bonus allegedly became the breaking point that led to a fatal confrontation.
That confrontation is now at the centre of a homicide investigation in Tokyo.
A 45-year-old man, Masahiro Yamanaka, was arrested on suspicion of killing his boss, 44-year-old company president Akihiro Kawashima, at Kawashima’s apartment in Ota Ward, according to Japanese media.
Police say confrontation took place at boss’s apartment
Police believe the incident occurred between the evening of Jan 7 and the morning of Jan 8. During questioning, Yamanaka reportedly admitted to confronting Kawashima at the apartment, later claiming he only intended to threaten him.
“I did stab him, but I didn’t intend to kill him,” he told investigators, according to The Yomiuri Shimbun.
Investigators said evidence at the scene suggested Kawashima attempted to defend himself.
A fruit knife believed to have been brought from Yamanaka’s home was recovered, and footprints stained with blood were found inside the apartment and on an emergency stairway, reported Mothership.
Bonus cut emerges as key possible motive
Attention has since turned to a possible financial motive. Investigators say Yamanaka told police his year-end bonus had been reduced without explanation.
He claimed his bonus was cut from the equivalent of one and a half months’ salary to one month’s salary. A pay stub reflecting the reduced amount was found at his home.
He also reportedly expressed deep dissatisfaction with workplace management and his boss’s attitude, telling investigators:
“I came to believe that if words didn’t work, I had to make him change his mind even if it meant making him suffer,” as quoted by Yahoo News Japan.
Surveillance footage tracked his movements
Security camera footage helped police trace Yamanaka’s movements on the day of the incident. Cameras showed him leaving his home in the late afternoon, entering Kawashima’s apartment building shortly before 6pm, and leaving about two hours later.
Footage also suggested he changed clothes before and after the incident. Investigators believe he later met a friend at a restaurant before visiting several bars into the early hours of the morning.
The following day, officers intercepted him at Tokyo Station as he was heading toward a Shinkansen platform.
As the investigation widened, Japanese media reported that Yamanaka and Kawashima had known each other since high school and remained close for years.
Kawashima had invited Yamanaka to join his company four years ago, hoping he could act as a bridge between management and staff. The two travelled together for work, and Kawashima was said to have been deeply supportive during key moments in Yamanaka’s life, including his wedding.
Mother issues public apology
Following the arrest, Yamanaka’s mother issued a public apology, describing her son as a gentle child who disliked violence.
“If he had problems at work, he should have walked away,” she said. She added that while her son must atone for his actions, “Kawashima’s life will never return.”
Police say investigations are ongoing to determine whether the attack was planned in advance and whether the alleged bonus dispute was the main trigger behind the case.
