子
This Chinese character means child.
You can watch how to write this. - (「子」の書き順（筆順）動画 - 漢字書き順辞典)
There are 2 main ways to read this, "こ" or "し".
"親子 (おやこ)" means parent and child.
"子ども (こども)" also means child.
"男子 (だんし)" means boy, and "女子 (じょし)" means girl.
"男 (だん, おとこ)" means male, and "女 (じょ, おんな)" means female.
Adult is "大人 (おとな)" in Japanese.
Generally, at the age of 18 or 20, a person is treated as an adult for legal purposes.
Cigarettes, alcohol, voting rights, contracts, and so on.
By Higashi-Mikawa Kyōjindō Shujin (東三河狂人堂主人)