A tragic case has unfolded at the Hokkaido District Court as Kosei Yuka, the then-19-year-old defendant, faced her fourth trial on March 4, 2025, related to the shocking murder of Riko Uchida, 17, who was pushed from a bridge, resulting in her death. Throughout the trial, Kosei has shown deep remorse, repeatedly stating, "It is unforgivable, I am truly sorry," as she addressed the public and those affected by her actions, reflecting the heavy emotional toll this tragedy has invoked.
The murder occurred back in April 2024, when Kosei and her co-defendant, Uchida Riria, now 22, reportedly seated Riko on the railing of the Kamui Kotan bridge and forcibly pushed her off—an act described as not only reckless but chilling. The events were allegedly fueled by personal grievances, stemming from Riko posting photos of Uchida without consent, which escalated tensions and led to drastic actions.
At the trial on March 4, Kosei, under questioning from her defense attorneys, recounted the incident but was met with contradicting statements from Uchida. Kosei said, “Uchida pushed Riko’s body,” attempting to distance herself from the act, claiming she reached out to help her friend after the push. This statement presents both the complexity of her involvement and her struggle to navigate the pressures from Uchida not to reveal the truth. Uchida's testimony reportedly claims she left the scene immediately after the push and assumed Riko had attempted suicide, stating, "I heard her scream, and then I heard the 'don' sound," highlighting the divide between the two accounts.
The tension and manipulation between the two girls were evident during the line questioning. Kosei described how she felt compelled to obey Uchida because she was often called her "aibou" (partner) and pressured not to anger her, saying, "She could be nice but also put pressure on me. I wanted to tell the truth but didn’t know what would happen to me if I did." This admission reveals not just her fear but the toxic dynamics often found within peer relationships, especially among young individuals.
Compounding the tragedy are at least 1160 messages exchanged via LINE between the two girls leading up to and following the event. The content of these messages included discussions about Riko and their plans, demonstrating both forethought and planning. On April 18, just prior to the murder, Uchida reassured Kosei, “Relax, it's okay, even if they search, nothing will come up,” implying her confidence about evading accountability for their actions. Just days later, they were implicated in the fatal encounter.
While Kosei has admitted her role during the initial hearing, where she recognized the indictment against her, the legal teams remain divided. The prosecution insists Kosei played an equal role alongside Uchida, arguing, “She was actively involved,” whereas the defense maintains her involvement was more suggestive and her actions were one of compliance rather than action. They argue Kosei was manipulated, using her age as part of their defense strategy to limit the culpability of her actions.
Reflecting on the court sessions, it’s important to recognize the enduring impact this case has had on the community. With intense public interest, the courtroom has been filled with spectators eager to witness proceedings, with hundreds lining up for limited seating.
The trial is set to conclude on March 5, 2025, with the verdict expected on March 7, 2025. The outcome will surely resonate beyond the courtroom as discussions of youth crime, peer dynamics, and the potential for redemption continue to fill societal discourse. Kosei has expressed, amid tears and apologies, hope for recognition of the truth, demonstrating the complexity of emotions surrounding such actions. This case serves as a stark reminder of the tragic consequences of youthful mistakes and the severe outcomes of peer pressure.