Kiyoomi and Hajime : volleyball players
Toru and Atsumu : star cheerleaders
They don't even know how it happened, but Kiyoomi and Hajime both like Atsumu and Toru at the same time! As well as each other, you guessed it. SakuatsuIwaoi was blooming.
Both Sakusa and Hajime knew this, but they didn't know if Atsumu and Oikawa felt the same. They only realized it about 2 year ago (they're in seniors in college), when They slept together, due to being drunk and didn't feel disgusted or horrified...it felt right.
And when Toru and Atsumu had a heated make-out session as 'besties' during a game of spin the bottle where neither felt jealous in fact they were turned on.
Currently, the 4 were at a different college party celebrating their school winning nationals. The 4 were sitting on the hoods of Kiyoomi and Hajime's cars drinking.