Jin walked with the others, their knife at the ready and their eyes constantly scanning for danger. If Jin was a bird, their feathers would be standing on end. Despite trying to tell themselves that this wasn't real, that this was just some horror movie nonsense, the memory of pain was far too real to really convince them otherwise. The only thing keeping them from blind panic was the fact that there were two other people now.

Ryoma-senpai could handle himself, but Jin wasn't about to let the girl - Ai, wasn't it - get hurt. That was one of the few things Jin held dear- people who weren't involved in the fighting shouldn't be dragged into it. And if Ryoma had the same thing Jin had, but Ai didn't, then obviously she was just an unlucky bystander.

Speaking of... 

"Here." Without preamble, Jin closed up the knife and offered it to Ai. "You need to be able to protect yourself. Just in case." They demonstrated a quick jab, as if holding an invisible weapon. "Do it real quick, like you're throwing a punch." Pausing for a moment, Jin looked Ai up and down. "You don't look like you throw many punches. Um." This was harder to explain than Jin realized. "Strike like you're trying to touch a hot stove. Don't let your hand linger, just... Jab, just like that."