Jung-min (played by Kim Kyu-na) is a protagonist in SPEEDY!.
Dong-hyun (played by Leem Seung-min) appears in SPEEDY!.
Principal (played by Hong Sung-choon) appears in SPEEDY!.
Brother (played by Bae Yeon-woo) appears in SPEEDY!.
Aunt (played by Ban Hye-young) appears in SPEEDY!.
