Lee Jung-jae as Choi Ik-ho[4][5][6]

Shin Ha-kyun as Ace

Lee Sung-min as Choi Young-ho

BoA as Soo-kyung[7][8][9][10]

Kim Eui-sung as Detective Do

Bae Sung-woo as Axe, gang member

Son Ho-jun as Jae-yeol, president of Ik-ho's fan club

Choi Woo-shik as Guru, hacker

Ryu Hye-rin as Twitter girl

Kim Yoon-seong as Department head Jo

Park Doo-shik as Detective Nam

Ra Mi-ran as Young-ho's wife