Japan Executes 'Twitter Killer': The Shocking Case That Changed Social Media and Crime Discourse

A Serial Killer's Execution: The End of Japan's 'Twitter Killer'

On June 27, 2025, Japan executed Takahiro Shiraishi, the notorious 'Twitter Killer', by hanging at the Tokyo Detention House. This marked the first use of capital punishment in Japan since 2022, closing a case that had haunted the nation since 2017. Shiraishi, 34, was convicted of murdering and dismembering nine people—eight women and one man—whom he lured through social media, specifically Twitter (now X). His execution was carried out in secrecy, with details only released after the fact, following Japan’s strict protocols for death row inmates. Justice Minister Keisuke Suzuki stated the decision was made after careful consideration, emphasizing the 'extremely selfish' motives and the profound shock the crimes caused in society.

The Modus Operandi: How Social Media Became a Hunting Ground

Shiraishi’s crimes exposed a dark side of social media in Japan. Between August and October 2017, he used Twitter to find young people expressing suicidal thoughts. His profile presented himself as someone willing to help those in pain, even offering to die alongside them. Once he gained their trust, he lured them to his apartment in Zama, Kanagawa Prefecture, under the pretense of assisting with suicide. There, he strangled his victims, sexually assaulted several of them, and dismembered their bodies, storing remains in coolers and containers. The victims, aged 15 to 26, were mostly vulnerable young women, and the only male victim was searching for his missing girlfriend.

Uncovering the 'House of Horrors': The Police Investigation

The case broke open on Halloween 2017, when police, searching for a missing 23-year-old woman, discovered body parts in Shiraishi’s apartment. The scene was described by media as a 'house of horrors', with coolers and toolboxes containing severed heads and bones stripped of flesh. The investigation revealed that Shiraishi had contacted his victims through their public posts about suicide, exploiting their vulnerability for his own gratification. His arrest and confession shocked Japan, a country with a low crime rate but a high suicide rate, and led to widespread calls for tighter regulation of online spaces.

Debate Ignited: Suicide, Social Media, and Legal Reform

The 'Twitter Killer' case ignited fierce debates in Japan about how suicide is discussed online and the responsibilities of social media platforms. In response, Twitter updated its policies to prohibit encouraging self-harm or suicide. The Japanese government also hinted at new regulations for websites and social media platforms that discuss suicide. The case highlighted the risks faced by vulnerable individuals online and the need for better mental health support and digital literacy. It also underscored the challenges in balancing free speech with the prevention of harm in digital spaces.

Japan's Death Penalty: Public Opinion and International Criticism

Japan is one of the few industrialized democracies, along with the United States, that retains the death penalty. Executions are carried out by hanging, and inmates are informed only hours before. Human rights groups have criticized this practice for causing psychological distress. Despite international pressure to abolish capital punishment, public support in Japan remains strong, especially for cases involving heinous crimes like Shiraishi’s. As of June 2025, there are about 100 inmates on death row, with nearly half seeking retrials. The execution of Shiraishi has reignited both domestic and international debate on the future of the death penalty in Japan.

Community Reactions: Outrage, Relief, and Lingering Questions

Japanese online communities and forums such as Naver, Nate, Instiz, DC Inside, and Efem Korea have been flooded with reactions. Many users expressed relief at the execution, feeling justice was served for the victims and their families. Others voiced concern about the underlying issues of mental health and social isolation, questioning whether enough is being done to support vulnerable youth. Some comments criticized the media for sensationalizing the case, while others debated the ethics of capital punishment. The case also drew attention from international fans of Japanese culture, who were shocked by the brutality and the role of social media in enabling such crimes.

Cultural Context: Suicide, Social Isolation, and Digital Vulnerability in Japan

To understand the impact of the 'Twitter Killer' case, it’s important to grasp the cultural background. Japan has long struggled with high suicide rates, especially among young people. Social isolation, academic and work pressures, and stigmas around mental health contribute to the problem. The rise of social media has provided both support networks and new risks, as seen in this case. The incident led to increased awareness and policy changes, but also highlighted the ongoing challenges in addressing mental health and digital safety in Japanese society.

Fandom and Media: How True Crime Shapes Public Perception

The 'Twitter Killer' case has become a subject of fascination and horror in Japanese and global true crime communities. Documentaries, news specials, and online discussions dissect every detail, reflecting a broader trend of true crime media influencing public understanding of criminal justice and mental health. Fans and critics alike debate the ethics of consuming such stories, the responsibilities of platforms in moderating content, and the ways in which media coverage can both inform and sensationalize. For international readers, this case serves as a stark reminder of the complex interplay between technology, society, and the law in the digital age.