Running Man Cast

1. Kim Jong-Kook
2. Yoo Jea-Suk
3. Kang Gary
4.Ji Suk-Jin
5. Lee Gwang-Soo
6. Song Ji-Hyo
7. Lizzy
8. Song Joong-Ki
9. HaHa

Relationship
1. Monday Couple (월요커플) : Gary & Ji-Hyo.
2. Suk Brothers (석브라더스) : Yoo Jea-Suk & Ji Suk-Jin.
3. Kim Jong-kook and his two kids (김종국과 아이둘) : Jong-Kook,Gary & HaHa.
4. Song-Song Couple (송송커플)
    Song-Song Siblings (송송남매) : Ji-Hyo & Joong-Ki.
5. Same-Aged Friends (동갑내기) : Joong-Ki & Gwang-Soo
6. Jail Regulars Trio (감옥 단골 3인방) : Gwang-Soo, Suk-Jin & Jea-Suk.
7. My Big Brother and My Little Brother (우리 형, 내 동생) : Jong-Kook & HaHa.
8. New Dumb and Dumber (신형 덤앤더머) : Suk-Jin & Gwang-Soo.

Source : Wikipedia & Tumblr