Real name: Kim Jisook (김지숙)
Nicknames: Sookie, SSook, Bolmae, More Charming By The Day
Birthday: July 18, 1990
Height: 164cm
Weight: 40kg
Blood Type: A
Position: Main Vocal
Color in Rainbow: Green.
Sub-Unit: Rainbow Pixie 
Education: Graduate of Hanyang Female University, majored in music.
Shortcomings: Short-tempered.
Look Likes: Kim Taeyeon (SNSD)

- Jisook was recommended to join Rainbow by former Kara member Kim Sunghee
- Jisook is mischievous and talkative
- She is known for her bright and cute image
- She is a fixed reporter on KBS Entertainment Weekly
- She can drink yogurt really fast and eat an entire pizza
- She is good at nail art, calligraphy, drawing, cooking and making stuff
- She was in a rock band during her high school days
- She is fan of Rilakkuma and Despicable me