Someone obsessed with the anime/manga Kuroshitsuji, esp. someone who has merchandise bearing a prominent symbol from the show/manga (a pentagram).
Person 1 : Dude you have a pentagram on your bag, are you a Satanist?
Person 2 : Nah man, I'm a shitsujiist.
Person 2 : Nah man, I'm a shitsujiist.
by Grbean February 06, 2011