- stage name: cheng xiao (성소/程瀟)
- birth name: cheng xiao xiao (程瀟瀟)
- korean name: jung seongso (정성소)
- position(s): main dancer, sub vocalist, visual, face of the group
- sub unit: wonder
- birth date: july 15, 1998
- birth place: shenzhen, china
- zodiac sign: cancer
- blood type: b
- height: 167cm (5ft. 6in.)
jun 19 2017 ∞
jun 20 2017 +