They fought over who can wear the bowl haircut and who has to stop.
But aren’t MOV and Kuroda friends?
Spoiler
MOV was here, Nuki is a loser
Fujiwara the best. I heard he was Yakuza.
What had happened was that Kuroda wanted MOV to be the big candle at his natural 23rd but MOV had plans with his girlfriend to go CUE hopping while Nuki happened to have a day off at the same time. Kuroda not having anyone to take the spot, gave it to Nuki but he failed to realize that Nuki doesn’t concern himself with the same things that Kuroda does. This created lots of conflict and eventually one of them found the other in Grand Finals where they will both meet their destiny.