Takes place in the present day (to the extent possible). It begins with Taki Kazuya (still an FBI agent) in New York City investigating a series of grisly vampire-like murders. As it is clear he can't rely on the Riders for help (Hongo Takeshi tends to appear and disappear like the wind), he has built his own Rider Suit, homaging Skull Man and informally known as "Taki-Rider". Taki is more than man enough to take on the Mooks, but when the man behind the plot shows up... so does Hongo and his Scarf of Asskicking. You can read the manga in english here