The problem was, even in the midst of a great tragedy, Fubuki still went around playing practical jokes on everyone. It was his part in keeping the spirit or everyone up.
Although, sometimes, Fubuki truly understood the gravity of the situation and realised that no amount of practical joking was going to make anyone happy. Sometimes, even he was unhappy.
But, most of the time he didn't, so everyone always had to be on the lookout. No one knew when Fubuki could pop up, or trip you up, or do something else silly.
After all, there was always trouble lurking.