Daichi - His usual calm demeanour is replaced with a dazed and grumpy man who isn’t ready to deal with anyone’s shit today. People consider him scary when he’s angry, but nobody is sure if anybody has lived to tell the tale of angering a hungover Daichi.
Sugawara - With a brave face, Suga downs as much water as he can trying to flush the hangover out of his system before carrying on with his day as usual. The caring side of him still showing but very quick to disappear if overwhelemed with drama.
Asahi - Many people see Asahi as intimidating on a normal day. When he’s hungover, there really is something to fear. His gentleness is abandoned as a hulking grump walks around the school.
Tanaka - Tanaka is an advocate of the “take small amounts of vodka” approach to cure his hangover. Enough to leave him still sober throughout the day with a little bit of a buzz.
Nishinoya - There is nothing that can get Noya to try and go to class with a hangover. It’s a sickness worthy of a day off in his eyes. Even if it’s not particularly strong or if it goes away halfway through the day, he’s quite content to just lay back and sleep it off until the next day.
Hinata - Hinata’s eyes scream death as people see him the morning after a bout of drinking. Any motivation or energy was sapped out of the boy as he struggles to cope with life while hungover.
Kageyama - Kags tries to use a ‘scientific’ approach, that is, just doing what he reads on the internet will help get rid of his hangover. The first two hours of his morning are spent trying crackpot methods of recovery, very few of which work. Those that do are probably placebos.
Tsukishima - Captain Grumpy himself is understandably pissed as he wakes up with a splitting headache and the screeching of the alarm clock ringing in his ears. He wouldn’t try to take measures to deal with a hangover, and would just grit through it for the rest of the day, complaining to anyone in sight.
Llamaguchi - Yama stays curled up in a ball in bed pretending that he is dead because he sure feels that way. Unless somebody came in to give him something to help him out, he wouldn’t even leave for the entire day.