Corpse Party - Seiko's Birthday

It's Seiko's birthday. Naomi, Ayumi, Satoshi, Mayu, Mrs. Yui, Morishige, Yoshiki and even little Yuka are invited. Whatever will happen, nobody knows. (btw, if grammar, spelling, word choice, whatsoever is wrong, tell me, and I'll be on it. I am half Dutch half English afterall.)