Tsukuyomi - Moon Phase

Synopsis

From Tokyopop:
When you come from a family of exorcists and mediums, you're expected to have certain powers. But despite having a psychic lineage, Kouhei Midou can't predict the future, nor can he see dead people. He's powerless in every sense of the word. However, he does think fast on his feet--and with a little help from his psychic cousin Seiji, he's an amazing crime solver.
The mystery he wants to solve more than anything is his mother's tragic disappearance. But it isn't easy... especially in this world, where nothing is as it seems. Cats talk, blood-sucking vampires roam the earth, and monsters eat guys like Kouhei for breakfast. Can Kouhei survive this chaos long enough to find the mother that he's lost?!

Synopsis & details from MangaUpdates