[Haslock/Yonhap]
[Haslock/Yonhap]

A string of incidents in which students tampered with classmates' tumblers — slipping in detergent, sleep aids and other foreign substances — has prompted schools and education authorities across Japan to tighten safety measures. As parental anxiety grows, a fingerprint-locked tumbler has entered the market and drawn wide attention.

According to AERA, a weekly magazine affiliated with the Asahi Shimbun, students at an elementary school in Suginami Ward, Tokyo, noticed strange smells and tastes resembling detergent or soapy water in their drinks and spat them out in February and March 2024.

Last September, a student at an elementary school in Adachi Ward, Tokyo, was found to have put a sleep-inducing drug into another student's tumbler. Similar cases involving disinfectant alcohol and magnets were also reported at schools across the country.

The shock deepened in May, when a teacher at an elementary school was caught engaging in inappropriate conduct involving a student's tumbler.

In response, the Suginami Ward Board of Education revised its guidelines to require students to keep their tumblers beside the teacher's podium rather than in lockers at the back of the classroom, and to carry them at all times when moving between rooms.

The board also established a dedicated support unit to respond quickly to conflicts within schools, and strengthened its protocols by requiring staff to report suspected tampering to police immediately.

Growing unease has fueled demand for related products. The "Cimon," a fingerprint-locked tumbler released last September by Haslock, an Osaka-based sports fashion company, sold more than 10,000 units within six months of its launch.

The tumbler's lid cannot be opened without a registered fingerprint, blocking access by third parties. Originally developed to prevent doping in athletes, it has recently gained traction among parents of elementary school children as a safety product.

Observers note that school safety concerns in Japan have expanded beyond conventional bullying to what is being called "foreign-substance pranks" — targeting individual students' food and drinks — and that this trend is emerging as a new management challenge for schools.

Legal experts warned that while students under 14 cannot face criminal punishment, their parents may be held civilly liable for damages, and those aged 14 and older could face charges of property destruction or bodily injury.


rainbow@heraldcorp.com