Jimin

Full name: Park Jimin
Nickname: Jimin
Best friend: Yoongi
Rival: Taehyung
Crush: Jungkook
School: 3rd year (high school or whatever)

Taehyung

Full name: Kim Taehyung
Nickname: Tae
Best friend: Hoseok (I'll just call him J-Hope in the fanfic)
Rival: Jimin
Crush: Jungkook
School: 3rd year (high school or whatever)

Jungkook

Full name: Jeon Jungkook
Nickname: Jungkook
Best friend: Yugyeom
Rival: none
Crush: GD (G-Dragon)
School: 1st year (high school or whatever)