The way you hold me Omi-Omi

(Cover art not mine. Credits to the owner)

Kageyama and Hinata are tying the knot in Brazil, and the entire gang is joining in on the celebration. Hinata, perhaps "accidentally" (or not), arranged for Sakusa and Atsumu to share the same room at the hotel where everyone is staying for the wedding.
To everyone's surprise (not Hinata's), there's only one bed in the room.

or

Kiyoomi and Atsumu find themselves sharing close quarters for an entire week, and from the moment they step into that confined space, chaos ensues. It seems that every possible mishap is on the agenda, and the situation only goes downhill from there.

or

The two idiots are forced to face their feelings thanks to Hinata Shoyo and his once-in-a-lifetime good idea.

(A little bit inspired by the song Holy by Justin Bieber 'cause Sakuatsu is all I think about when I hear that song.)