level two of the syndrome, karamatsu

Karamatsu was sitting by himself outdoors, on the damp grass. It was relaxing, with just the sounds of nature.

“Ichimatsu, put that knife away.” Karamatsu said, shaking slightly.
“I’m slicing an orange. So no.” the younger brother replied, giving no concern to the other’s odd behavior.
“You’ll cut someone with that!” Karamatsu raised his voice, making Ichimatsu flinch.
“What the hell is wrong with you?”
Karamatsu fell silent.
“Don’t hurt yourself…” he walked out shortly after.