1. H.U.B's Hyosun, former April's Hyunjoo
When the two revealed their friendship, everyone was shocked because the two couldn't be more different: Hyosun has the tomboy, strong vibe, while Hyunjoo has the cute, innocent vibe. However, the two revealed that they were actually close friends from school - friends who even relied on each other during hard times. They did have friction between each other during an episode, but it was only because they were so close and relied on each other more than they did on others. The fight upset both of them so much that they cried, showing just how much they meant to each other. Don't worry, though - they've made up, just like good friends do.
2. Big Star's FeelDog, MYNAME's Seyong
FeelDog and Seyong had talked about being close friends all the way from episode 1, so fans were just waiting to see the two interact. They did, throughout the show, but didn't get a chance to really show how close they were until the 2nd round where they were put on the same team. The pair joked around and poked fun at each other as close friends usually do, and it was nice to see both of them get louder and more excited purely because they were on the same team. Make sure to watch the Red Team's practice scenes during the 2nd round to see the two besties in action.
3. SONAMOO's Euijin, model Lee Bo Rim
Out of this entire list, this pair is the only one who met on the show instead of before. Euijin was Borim's dance teacher during the first round, and since them, Borim has heavily relied on Euijin even though the blonde is younger. Borim herself talked about how great Euijin was, and Euijin relayed how much she wanted to see Borim blossom to her full potential. The duo has been on the same team for every single round together except one, making them the pair to be on the same team the most often.
4. Mad Town's Lee Geon & Daewon, former BEAT WIN's Jungha
The trio's friendship was revealed quite early in the episode, where Daewon called out Lee Geon to express his disappointment on Lee Geon leaving him behind to hang out with Big Star members instead. The two Mad Town members revealed that they had also known (former) BEAT WIN member Jungha for over 10 years, as the trio had been friends since elementary school. The three finally got to be on the same team in the latest mission, and were shown working extra hard because it was a rare chance for them to release anything together.
5. Former The Ark's Euna and Suji
Both Euna Kim and Lee Suji are from the now-disbanded group The Ark, so it's no surprise that they're close. However, even considering that they were from the same group, the two are extra close. Euna chose Suji first and foremost when she was picking her team, and the two were even spotted sleeping on the same bed during break time despite other empty beds around. Suji and Euna have talked about their friendship often on the show - hopefully the two will get a chance to be in a group together once again.
6. Boyfriend's Donghyun, U-KISS' Jun
This is quite possibly the friendship that surprised most fans. Many didn't even know that Donghyun and Jun (who are 8 years apart in age) were even friends until recently, when Jun and Donghyun were filmed sharing a Montshell snack. Fans noticed that Jun talked informally to Donghyun, which would have been impossible unless they were close since Jun is so much younger than Donghyun. Donghyun finally satiated fans' curiosities when he revealed during a 'V' app that Jun had come seeking him out when he debuted as a later addition to U-KISS, saying he was a fan. (Jun has also said on a Japanese show that he was a fan of Boyfriend.) Donghyun recalled a cute story where Jun (who had been shorter than him when they first met) kept coming to see him and holding his hand, and when Donghyun asked him why, Jun stopped doing so and it made Donghyun a little disappointed.