- Full name: Son Chae-young
- Date of Birth: April 23, 1999
- Nationality: Korean
- Blood type: RH-B
- Group: Twice
- Agency: JYP Entertainment
- Debut: October 19, 2015
- Position in the group: Main rapper, sub vocalist
- Family members: Mom, dad, younger brother, Chaeyoung
- Nickname: ‘Chang’, ‘Baby Mengsu’- Mengsu means fierce animal
- Chaeyoung was interested in performing arts from a young age and started off as a children magazine’s model
