Kpop Invasion In Me

from left: Haha, Gary, Kim Jong Kook

Song Ji Hyo, Gary

The primary loveline of the show, they show interest in each other on Mondays, which used to be the day the show was recorded (later on the show was recorded on Mondays and Tuesdays, leading to jokes about the couple not being in effect on Tuesdays).

Song-Song Couple/ Song-Song Siblings

Song Joong Ki, Song Ji Hyo

This dynamic was made official in episode 23, though the couple's loveline attracted attention from episode 15 when Joong-Ki kissed Ji-Hyo on the cheek. They later evolved into a sibling-like relationship as the Song Song Siblings.

Same-Aged Friends

Lee Kwang Soo, Song Joong Ki

Lee Kwang-soo claims to be close friends with Song Joong-ki due to their same age (26), but Song Joong-ki would often deny their close friendship, leaving Kwang-soo appearing depressed. Song Joong-ki finally admitted their relationship in his leaving speech during the filming of his last episode.

Jail Regulars Trio

Yoo Jae Suk, Ji Suk Jin, Lee Kwang Soo

This trio is often eliminated the earliest during Bells Hide and Seek, and meet each other at the jail.

Suk-Brothers

Yoo Jae Suk, Ji Suk Jin

The two MCs have been close friends for more than 20 years and that they both have "Suk" in their name. However, Ji Suk-jin is always jealous of the good relationship Jae-suk has with Kim Jong-kook. In episode 27, Ji Suk-jin was referred to as Yu Jae-suk's "sunflower" (always facing towards him) and was officially christened as such in Episode 40.

My Big Brother and My Little Brother

Kim Jong Kook, Ha-ha

These two are often on the same team and they have an older brother/little brother relationship throughout the show.

New Dumb and Dumber/ Easy Brothers

Ji Suk Jin, Lee Kwang Soo

The New Dumb and Dumber relation was first depicted in episode 65, when they became a bumbling duo, acting similarly to the Dumb and Dumber couple of Family Outing They were rechristened the Easy Brothers when they were designated spies for Episode 68, and a clue was offered to the other members that threatened to reveal their identities. The clue was "Easy," a romanization of the combination of their surnames 이 (Lee/Ea) and 지 (Ji/Sy).