Shuichi was definitely surprised by the reason behind their interactions, but the main thing that he felt was concern. It worried him to hear that Kokichi hadn't eaten anything in the past few days. He knew that it was definitely unhealthy to go days without eating anything, so he hoped that the other was okay. Despite being starving, he noted that the werewolf appeared to be full of energy, although he wondered if he was genuinely energized or simply faking it to avoid creating concern.
"Well…maybe you should find something to eat," he suggested softly. "If need be, I could try to help you out. We may have just met, and, well, come to think of it, we don't even know each other's names, but I can't let you starve…"