Pleasure to meet you! I'm Sammy and I write Yu Narukami; he's soft-spoken and unassuming, yet quick to grasp things so if anything supernatural happens, he probably won't be weirded out by it. If anything, he'll pick up on the ropes and actually stay within the salt circle.
I've seen up to-- I believe the recent episode with Osiris? It's an awesome show and it makes me squee seeing one of the Winchester boys here.