I actually made a similiar small post a few weeks ago, but I uploaded some pictures on them instead. So here's a better, more "fulfilled" list on every (most of them) kpop groups out there~

 

 

                                         

 

 

2AM
Jinwoon: Name unknown (elder brother)

2NE1
- Bom: Go Eun (elder sister)
- CL: Harin (younger sister)
- Minzy: Name unknown (elder sister)
- Sandara: Durami (younger sister), Sanghyun [Thunder] (younger brother)

2PM
- Junho: Name unknown (elder sister)
- Junsu: Junhyun (younger brother)
- Nichkhun: Nichan (elder brother), Nichthima/Yanin (younger sister), Nachjaree/Sherleen (youngest sister)
- Wooyoung: Junhwa (elder sister)

4minute
- Hyuna: Hyunho (younger brother), Hyunsuk (younger brother)
- Jihyun: Name unknown (younger brother)
- Jiyoon: Jisoo (elder brother)
- Sohyun: Name unknown (younger brother)

After School
- E-young: Taejin (brother)
- Kahi: Jimin (elder sister), Jaewoo (elder brother), Jihye (younger sister)
- Jooyeon: Name unknown (elder sister)
- Jungah: Hyunsoo (younger sister)
- Raina: Name unknown (elder brother)
- Uee: Yoona (elder sister)

Apeace
- Hoyoung: Name unknown (elder sister)
- Wanchul: Name unknown (elder sister)
- Youngwok: Name unknown (elder sister)

 

A-Pink
- Chorong: Name unknown (elder sister), Seunghee (younger sister)
- Eunji: Minki (younger brother)
- Naeun: Seeun (sister)

 

B1A4
- Baro: Yoonji (younger sister)
- CNU: Name unknown (elder sister)
- Gongchan: Minwoo (younger brother)
- Jinyoung: Jiyoung (elder sister)
- Sandeul: Name unknown (elder sister)

Beast
- Dongwon: Dongha (elder brother)
- Doojoon: Doori (elder sister)
- Hyunseung: Geurim (younger sister)
- Junhyung: Junsung (younger brother)
- Kikwang: Hyekwang (younger brother)
- Yoseob: Haeyeon (elder sister)

 

Big Bang
- Daesung: Bora (elder sister)
- G-Dragon: Dami (elder sister)
- Seungri: Hanna (younger sister)

- Taeyang: Hyunbae (elder brother)
- T.O.P - Hye Yoon (elder sister)

 

 

Lots of sisters O__O Or is it only me who's seeing it? There was only 4 group that all the members had a sibling and poor Chansung forever alone kid XD