Okay kiddo, so birth control is something that helps people not have babies when they don't want to. In Japan, birth control is legal and easily accessible for people who want to use it. There are different kinds of birth control, like pills, condoms, and IUDs (which are like little devices put inside your body to prevent pregnancy). Some kinds of birth control need a doctor to give you a prescription, but others you can buy at a store.
A long time ago in Japan, people didn't talk about birth control very much and some people thought it was bad to use it. But nowadays, more and more people are using birth control to decide when they want to have children. Some people use birth control to prevent getting pregnant until they are ready, and some people use it because they don't want to have children at all.
In Japan, there are also government policies and programs to help people prevent unwanted pregnancies. For example, schools and community centers teach people about different kinds of birth control and how to use them safely. The government also provides funding for research on birth control and family planning.
Overall, birth control is a choice that people can make for themselves in Japan, and there are many options available for those who want to use it. It's important to talk to a doctor or other trusted adult before starting to use birth control to make sure you choose the right method for you and use it correctly.