On March 11, 2025, tragedy struck the Shinjuku Ward of Tokyo when 22-year-old Airi Sato, known uniquely as the popular live-streamer “Ai Saigami,” was brutally stabbed to death during what was likely her streaming session. Witnesses recounted horrifying details as the incident unfolded, leaving the community shocked and drawing attention to issues of personal safety within online environments.
The assailant, 42-year-old Kento Takano, was arrested at the scene under suspicion of attempted murder shortly after the incident, which occurred at approximately 9:50 AM. Eyewitness reports indicated Takano had approached Sato, wielding a survival knife with the intent to harm. It is estimated she was stabbed multiple times, particularly around her neck and chest, before the emergency services arrived. Tragically, Sato succumbed to her injuries about one hour and twenty minutes later at the hospital.
A shocking aspect of the event is the fact it reportedly took place as Sato streamed live video of herself walking through Tokyo. Prior to the attack, she had teased her viewers with the promise of documenting her walk around the Yamanote Line loop, which she mentioned during her live broadcast the previous day.
Witnesses shared harrowing accounts of the scene. A nearby construction company executive, 53, recalled distinctly hearing the victim's desperate cries of “Help me!” followed by the perpetrator’s unusual calmness as he stood near her. The male taxi driver, aged 52, described seeing the assailant nonchalantly filming Sato’s motionless figure, which was drenched in blood. “He kicked her head as he filmed—it was unnerving,” he recalled.
Another witness, Shuhei Kamizaki, 31, who worked nearby, mentioned seeing Takano holding Sato’s smartphone, seemingly documenting the moment. Takano reportedly raised his hands and confessed, “It’s me,” when police arrived on the scene, astonishing bystanders who did not initially perceive him as the criminal.
Further investigation revealed the troubling undercurrents behind the violence; Takano stated he had lent Sato over 2 million yen and expressed frustration over her failure to repay the debt. This financial dispute had reportedly escalated to the point where Takano consulted police last January. He claimed, “I wanted my money back,” which contextualizes his gruesome actions.
Sato was regarded as kind and compassionate by those who knew her. A friend who spoke with her just before the incident described her as “a gentle soul.” Those who gathered near the location after the incident laid flowers and paid their respects, mourning the loss of someone who had brought joy to many viewers online.
The crime has sparked heated discussions around the safety of live-streamers and the potential for personal conflicts, particularly those initiated online, to become dangerously violent. With video streaming increasingly prevalent, some are calling for stronger protections for individuals broadcasting their lives to the public.
Authorities noted the significance of the recorded footage from her streaming session and any insights it could provide about the moments leading up to her death. Takano’s history of lending money and his previous attempts to resolve the financial conflict indicate premeditated intent, which law enforcement is treating seriously.
After the stabbing, the area around Takadanobaba Station became engulfed with both emergency response teams and curious onlookers, drawn to the unsettling scene near the intersection of residences and shops approximately 350 meters southwest of the station.
Neighbors expressed their disbelief and concern for the safety of their community. A local housewife, 66, remarked, “It’s such a tragic event. I wish her peace.”
The case highlights not just the consequences of online interactions but also pushes forward discussions around mental health and the need for effective conflict resolution. Takano’s actions, stemming from monetary disputes, serve as reminders of the potential for everyday grievances to escalate horrifically.
Moving forward, authorities will likely be interrogated not only to ascertain the facts surrounding this case but also to explore preventative measures to avoid similar tragedies. With the tension between virtual interactions and real-world consequences evident, it will be imperative for all stakeholders—police, community leaders, and streaming platforms—to engage with this issue thoroughly.
Today, the case remains under investigation by the Tokyo Metropolitan Police, who have escalated the charges against Takano from attempted murder to murder based on the evidence collected and the overwhelming witness testimonies confirming the gravity of the attack.