Only moments ago Leon was alive and being dragged away to his execution Monokuma called 'The 1,000 Blows'. He saw all the students reactions before he was pummeled to death by baseballs. Even in the afterlife, he remembered all their faces. Even the horrified expression of his best friend witnessing his death.
To him, the afterlife as a ghost was pretty chill. Just he couldn't be seen by humans, and that was the part that sucked. But he could get their attention by messing with inanimate objects. But to him that wasn't good enough, he wanted to be seen and heard just like he was when he was alive.
He'd watch the rest of his classmates go on with their day so casually after voting to execute him. He was still sour about that, but he couldn't be mad at his best friend. Of course he missed them, especially since the voting board caught his eye when he was alive. His friend didn't vote for Leon, instead someone else. With that in mind, he was forced to check on how they were doing. He was honestly expecting the worst.