On January 10, 2025, an incident occurred where a Korean female student at Hosei University caused a ruckus with a hammer.

From the incident overview to the perpetrator's statement and local reaction, learn more about this shocking incident.

A shocking incident occurred at Hosei University in Japan. A Korean female college student swung a hammer, injuring eight students. The reason this incident is particularly noteworthy is because the perpetrator claimed that the motive for the crime was bullying.

1. Incident Overview – Hosei University Hammer Riot Incident
The incident occurred at around 3:40 PM on January 10, 2025, in a classroom at Hosei University's Tama Campus in Machida, Tokyo. Joo-Hyeon Yoo (22 years old), a second-year Korean female college student in the Faculty of Social Sciences, swung a metal hammer, injuring eight students in the head, arms, etc.

Fortunately, no one was in danger of losing their lives due to minor injuries, but the classroom was filled with shock and fear.

2. Situation at the time of the incident – ​​A thrilling moment in the classroom
At the time, there were about 100 students taking the class in the classroom.

About 15 minutes after class started, the incident suddenly occurred. The perpetrator, expressionless and swinging a hammer, indiscriminately attacked the students in front of him.

Then, when the hammer fell out of her hand and fell to the floor, she threw her cell phone on the floor and attacked him with her bare hands. The professor and security guard who were present at the scene arrived and subdued her, and the police arrested her at the scene.

3. Blunt tool used – hammer for construction site
According to the Metropolitan Police Agency announcement , the blunt weapon used was a metal hammer measuring 30 cm in length and weighing 360 g, a tool commonly used at construction sites.

The perpetrator reportedly stole the hammer from another classroom the same morning, leading police to believe it was a premeditated crime.

4. The perpetrator’s statement – ​​“It was because of bullying”

After his arrest, the perpetrator explained the reason for his crimes, saying, "I was ostracized by the group and built up resentment." He claimed, "I had no other way," but the victims stated during the police investigation that "I didn't even know the perpetrator" and "I had no relationship with her at all."

5. Your usual assessment of the offender – has there been any problem behavior?
According to the testimonies of students at Hosei University, the perpetrator had always shown violent language and behavior. Some students even responded by saying, "We knew she would cause trouble."

It appears that there were actions that caused anxiety in the surrounding area even before the incident.

Go check out the related news!

Korean woman in her 20s swings hammer during lecture at Japanese university, injuring 8 people… “Because I was bullied” (Supplementary report)

“To stop bullying, you have no choice but to hit”… 20-year-old Korean student in hammer incident sent to Japanese prosecutors

Korean woman in her 20s swings hammer during class at Japanese university… 8 people injured