(MAIN) Seo JooHyun / Seohyun / Seo (20) 

-Smartest student in faculty of law Dongguk University
-Rich, beautiful, and cute
-Caring her friends more than herself
-Dated twice
-Gang: GG

(CAMEO) Kim TaeYeon / Taeyeon / ByunTae (22)

-Student in faculty of law in Dongguk University
-Rich, Beautiful, cute
-Seohyun's bestfriend
-like to see handsome boy
-accidently fall for Jimin
-Dated N times
-Gang: GG

(CAMEO) Hwang MiYoung / Tiffany / Tiff (22)

-student in faculty of law Dongguk University
-Rich, beautiful, cute
-Seohyun's bestfriend
-Currently dating Cheolwoo
-Dated N times
-Gang: GG

(CAMEO) Choi SooYoung / Sooyoung / Tallsoo (22)

-student in faculty of law Dongguk University
-Rich, beautiful, cute
-Seohyun's bestfriend
-Siwon and Minho's sister
-Dating with a boy from different college
-Dated N times
-Gang: GG

(CAMEO) Kim Hyoyeon / Hyo (22)

-student in faculty of law Dongguk University
-Rich, beautiful, cute
-Seohyun's childhood bestfriend
-Know a lot about Seohyun
-Accidently fall for J-Hope
-Dated N times
-Gang: GG

(CAMEO) Kwon Yuri / Yul (22)

-student in faculty of law Dongguk University
-Rich, beautiful, cute
-Seohyun's bestfriend
-Dating with a boy from different college
-Dated N times
-Gang: GG

(MAIN) Jeon JungKook / Jungkook / Kookie (18)

-Freshmen in faculty of Law Dongguk University
-Rich, handsome, cute and lazy
-Playful, sometimes cool
-Falling in love with Seohyun
-Dated N times
-Gang: BTS

(MAIN) Kim TaeHyung / V / Taetae (18)

-Freshmen in faculty of Law Dongguk University
-Rich, handsome, cute, smart
-Playful, caring his friends
-Falling in love with Seohyun
-Dated N times
-Gang: BTS

(MAIN/CAMEO) Kim SeokJin / Jin (20)

-Smartest student in faculty of law Dongguk University
-Rich, handsome, cool
-Seohyun's college mate
-Mystery relation with Seohyun
-Dated N times
-Gang: BTS

(CAMEO) Jung HoSeok / J-Hope / Hope (22)

-Smartest student in faculty of law Dongguk University
-Rich, handsome, cute
-Playful, happy virus in gang
-Have some feeling toward Hyoyeon
-Dated N times
-Gang: BTS

(CAMEO) Min YooNgi / Suga (22)

-Smartest student in faculty of law Dongguk University
-Rich, handsome, cute
-Playful, caring his friends
-Seohyun's childhood friend
-Dated N times
-Gang: BTS

(CAMEO) Park Jimin / Jimin (21)

-Smartest student in faculty of law Dongguk University
-Rich, handsome, cute
-Playful, happy virus in gang
-Seohyun's admirer, everybody knows
-Love to teased Taeyeon
-Dated N times
-Gang: BTS

Others:

-Lee CheolWoo (22) -Tiffany's boyfriend
-Choi SiWon (22) - Sooyoung's elder brother
-Choi MinHo (20) - Sooyoung's younger brother
-Do KyungSoo (20) - Their friends
-Kim MinSeok (22) - Their friends
-A-PINK (18-22) - GG's enemy, BTS' fans

GG and BTS became a popular gang in Dongguk University, they had a lot of fans also enemy.

Sorry Not all of the members in it,
I can't take too much character. Sorry 
Enjoy it.