Train gropers in Japan

One of the most unfortunate aspects of using the train or subway in Japan, especially in crowded urban centers, is the risk of becoming a victim of chikan 痴漢, a commonly used term for sexual harassment or groping.

Although by no means exclusive to this country, incidences of chikan, although steadily declining in recent years according to police statistics, are still worryingly frequent in Japan. As reported by BuzzFeed News, a survey of 12,000 men and women aged between 15 and 49 conducted by the #WeToo Japan platform in August 2018 revealed that 70% of women and 32% of men had been sexually harassed on trains at least once in their lives.

Shachihata makes good on its promise

On May 13, 2019, in a tweet which went viral and provoked a heated debate on Japanese social media, illustrator Akubi (@AkubiHarubiyori) posted a manga recounting her experience as a schoolgirl when she was victim of chikan. The school nurse apparently advised her to defend herself by stabbing the groper's hand with a safety pin:

Understandably, the suggestion elicited numerous opinions, both for and against the proposed method of deterring would-be gropers.

Amidst all the individual responses to the tweet, one corporation's reaction immediately drew attention. Seeing an opportunity to address a problem facing Japanese society, Shachihata, a Nagoya-based company famous for making pre-inked rubber stamp products, tweeted the following:

It would now appear that these weren't just empty promises.

Shachihata's "Nuisance Prevention Stamp"

Here is Shachihata's meiwaku kōi bōshi sutampu or "nuisance prevention stamp."

In Japan, most incidences of chikan are considered violations of the meiwaku kōi bōshi jōrei 迷惑行為防止条例 or Nuisance Prevention Ordinance, a category which covers a broad range of crimes involving violence or behavior which offends public morals and disturbs public peace. However, since chikan is not technically the term used for the crime, meiwaku kōi ("nuisance") is often used as a euphemism.

According to its press release, the stamps use "invisible ink" which reacts to ultraviolet light, and affix a "hand shaped mark" onto the surface which appears colorless and transparent under a light or under the sun but is revealed under a blacklight. The stamp includes a locking mechanism and can be operated with one hand. It also includes a retractable reel with a portable blacklight which can be attached to a bag or a pocket.

Shachihata will put their stamps on sale in a trial run of 500 units from August 27th, 2019, with the intention of "testing its deterrent ability and its practicality." Based on the trial, they will take into account any feedback they receive, make further improvements and continue development towards a full release into the market.


Product Details

  • Name (JP): 迷惑行為防止スタンプ
  • Name (EN): Nuisance Prevention Stamp
  • Stamp type: Capless 9
  • Size of stamp imprint: 9 mm (0.35") width
  • Ink type: ultraviolet fluorescent ink
  • Imprint:

Trial run sales site

  • Official online store: Shachihata Antenna Shop
  • Trial run begins on August 27th, 2019, 13:00 (JST)
  • Units to be sold: 500

By - Ben K.