We're always looking for ways to stop bullying in the UK, but did you realise it's just as big a problem in Japan?
But instead of name-calling, the bullies tend to ignore their victims and the whole issue is kept very quiet.
That's partly because Japanese culture can be very private and polite and lots of people think it's rude to even mention the word bullying in public!
As a result, schools there are only just beginning to recognise the problem and do something about it.
Normally, TV crews aren't allowed to film in Japanese schools, but Newsround's Adam was let into one school to find out more.
Japan's top bullying expert Mr Ogi says kids bully each other to release stress
One pupil, 13-year-old Fumita, told him: "I think bullying happens a lot these days. There's a lot of bullying I've been hearing about on TV too, I think it's really sad."
Moeko, 13, said she put up with being bullied until she was invited to talk to a school counsellor: "I didn't want to talk about it, but after I talked about it, it got better."
Doing well in school is very important for Japanese children, but the country's top bullying expert, Mr Ogi, thinks that's making the problem even worse.
He said: "Students are very stressed out and they bully others to release that stress, but they don't realise the pain and hurt that they're causing."