Do you have someone that you consider to be your best friend? If you ask that question in one school in Denmark then the answer would definitely be no.
That's because at Bernadotte, a private school in Copenhagen, there is a ban on having just one best friend.
Instead, children are encouraged to make friends with as many people as possible as a way to make sure that bullying never happens.
There are other strict rules, including having to invite everyone in your class to your birthday party. The children are also told they cannot invite just one friend to play at their house and must ask at least three at any one time.
Newsround's Hayley went to Denmark to find out more.