I’ve said it before, but it bears repeating: Japan is a relatively safe country…but less safe if you’re a woman. The prevalence of train molestation and the rise in stalking incidents are but two examples.
In recent years, however, some men have taken to exercising their hatred of women in the most sneaky-ass way possible. The phenomenon is called butsukari ojisan, “bumping old men.” And while there are no official statistics behind it, online reports show it’s a real and vicious trend plaguing women in today’s Japan.
Butsukari ojisan: Assault by any other name
Reports of butsukari ojisan, or older men deliberately bumping women, crop up regularly on social media service X. One of the most famous examples is from idol Esaki Aoi (江﨑葵), a stage actor and member of the group Nijiiro no Hikō Shōjo. On October 20, 2025, she posted about how a man bumped into her full-force, calling her “ugly” (ブス; busu) to boot.
“I chased him right down immediately and responded with a tackle about three times as hard, calling him ‘baldy’ [ハゲ; hage] for good measure.”
(And yes, calling a working idol “ugly” is a real stretch. As commenters noted, busu is a general insult men hurl at women they hate; it has nothing to do with the person’s actual appearance.)
The replies reinforce just how prevalent this phenomenon is. One woman says she saw a man hit a pregnant woman on a crosswalk. Another said that a man came straight at her while she was walking with her husband.
The case of one long-haired man shows exactly what’s behind these attacks. He reported that he got bumped in Ueno, and the bumper looked shocked that his victim, whom he expected to be a woman, didn’t go flying. Others have reported seeing men deliberately target a woman’s chest, and even targeting other women after missing their first target.
Why men do it (and who they target)
Most respectable men are oblivious to this phenomenon, as it seldom happens to them and often happens when perpetrators think other men aren’t looking. And there are, as one might expect, cases of butsukari obasan (bumping old women). The most infamous was a February 25, 2026 case reported by The Guardian, in which a masked woman shoved a young Taiwanese girl to the ground in Shibuya Scramble.
Social media evidence makes it clear, however, that the majority of victims are women, and their attackers are men. What motivates this hateful, anti-social behavior?
FNN Prime Online gives a glimpse into one man’s motivations. In 2020, 45-year-old Nagata Daisuke was arrested in Tokyo on suspicion of bumping six women, reportedly aiming squarely at their chests. While he denied the charges, he admitted to being a serial bumper.
“Once, I happened to bump someone getting off a train,” he said. “It felt good. I did it a dozen-plus times.”
Some women feel men select them due to their size or appearance of vulnerability. One woman who goes by the pseudonym Rina, a small woman at 150cm and 40kg, said she was hit so often that she stopped taking the train. Another woman said she repeatedly got bumped at Shinjuku Station until she started wearing sunglasses and “hard-edged” outfits.
Ultimately, the driving factor may be the misogyny built into Japanese society. Toyo University criminologist Kiryū Masayuki says “misogyny may be one of the major reasons” behind the phenomenon. The belief that men are superior to women still lingers in society at the same time that job insecurity has worn down traditional images of manhood.
Based on his own non-systematic analysis of cases, Kiryū backs up the women who say men choose them because they look weak. “It’s the same principle as a road-rager who steers clear of a dangerous-looking person in a luxury car,” he told Toyo Keizai.
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What can women do? Not much, it seems
Kiryū says men commit this behavior because they’re confident they won’t get caught.
Sadly, those men are usually right.
While butsukari ojisan may sound like a cute, trendy name, critics contend that it’s no more than a euphemism for assault. On paper, it carries up to two years’ detention and a fine of up to ¥300,000 (~$1.9K). If the assault causes injury, penalties rise to up to 15 years or ¥500,000 (~$3.2K).
Unfortunately, without surveillance camera proof, a case often drops to plain assault, and a first offense can end in a summary fine.
Some men are let off the hook with no real explanation. A Seinan Gakuin University associate professor was arrested three times in April and May 2025 for swinging his bag into passersby on his commute in Sawara Ward. Before his arrest, local news reported that a man swinging a bag on that street mostly targeted women, and left one male cyclist bloodied. Despite this, the Fukuoka Summary Prosecutors Office declined to indict him.
The lack of police action causes some women to take the law into their own hands, in the same way that some women have responded to train molestation with safety pins. After a woman was bumped to the ground at a July 2025 concert at the Tokyo Dome, bystanders and her daughter chased the dude down.
However, as some people noted in replies to Esaki Aoi’s post, standing your ground can be risky. It can invite an even more violent reaction from a man who’s already shown himself open to assaulting women.
Retaliating can also leave victims vulnerable to prosecution themselves. In one case where a victim braced themselves and met an attacker head-on, a lawyer warned they could be charged with assault for deliberately not stepping aside unless they could prove it was self-defense.
Reporting the hot spots
There aren’t any solid statistics on this, but I wouldn’t be surprised if these assaults were under-reported. We know from at least one study that around 80% of train groping cases may go unreported, because victims are convinced the police won’t take their complaints seriously.
As with train groping, the combination of a lack of official data and inaction has left private entities to fill the gap. The company Gaccom launched a website, Gaccom Safety Navi, that enables people to log cases of assault or suspicious persons. The site shows at least 100 suspected cases of butsukari logged between 2016 and 2025.
In the end, public ridicule may be the best weapon that women have at their disposal. One X discussion says that butsukari doesn’t happen as often in Osaka because men know that Osaka women won’t take any shit and will talk back. In one anecdotal case, a group of older Kansai women shouted “Apologize!” (謝らんかい！) in unison at a male attacker.
Of course, the ultimate remedy is for men to stop taking their social frustrations out on women. The second best remedy is for police and prosecutors to believe women and hold men to account for their crimes. But I won’t deny the power of a good public shaming.
Keep reading
Sources
駅の改札で真正面からタックルしてくる「ぶつかりおじさん」 被害に遭った女性は「後ろへ吹っ飛んで転んだ」 キャリコネニュース（ライブドアニュース）
新宿「ぶつかり男」 わいせつ目的の可能性！？ “わざとぶつかる”心理とは AERA dot.
被害女性たちが明かす「ぶつかりおじさん」の恐怖 その悪質な実態が伝わりにくい呼び方にも異論続々「シンプルに暴行犯」「通り魔暴行犯って呼び名でいい」 マネーポストWEB
【実態】「ぶつかりおじさん」に「体当たり女」被害経験者は14%で地域別1位は東京都…専門家「報復は過剰防衛にも…駅員・警察に“防カメ映像確認”申し入れを」 FNNプライムオンライン
女性の胸狙う“ぶつかり男”逮捕 容疑否認も過去には「感触が良く十数回やった」 FNNプライムオンライン (archived)
「ぶつかりおじさん」に何度も狙われた女性「小さくて弱い女が吹っ飛ぶのが面白いのだと思う」…被害に備えて空手習う 弁護士ドットコム
ぶつかりおじさん、ド派手な通勤服で「被害ゼロ」になった女性の証言「彼らは見た目でターゲットを選んでいる」 弁護士ドットコム
A young girl is knocked over at Tokyo crossing – what’s behind Japan’s ‘bumping’ trend? The Guardian
東京ドームライブ帰りに「ぶつかりおじさん」被害→女性たちで取り押さえ 負傷女性が語った恐怖の瞬間 弁護士ドットコム
暴行容疑で３回逮捕された西南学院大准教授の男性を不起訴…福岡区検「諸般の事情を総合的に考慮した」 読売新聞オンライン
卑劣！すれ違いざまに鞄ぶつけてくる“迷惑男” 偶然装う“微妙な当て方” 5回も狙われた女性が被害届【福岡発】 FNNプライムオンライン
「ぶつかりおじさん」６４歳、女児に体当たりし傷害容疑で逮捕…警戒する教員が「現れた」と警察に相談 読売新聞オンライン
「一人で登りたいのに」女性登山者についてくる“おじさん”、「迷惑」「怖い」の声…罪にならないの？ 弁護士ドットコムニュース（ライブドアニュース）
体型？それとも雰囲気？女性を狙う「ぶつかり男」も相手を選んでる…女性たちの体験談が話題に 神戸新聞NEXT
ホームや路上で女性にいきなり…｢ぶつかり男｣は罪に問えるのか？心理と対処法を専門家に聞く《5月には大学准教授が暴行容疑で逮捕》 東洋経済オンライン
大阪と東京は違う！？「ぶつかりおじさん」を撃退する大阪人のスキルが話題「おっさんどこ見て歩いとんねん！」 神戸新聞NEXT