Durarara!! Saika Arc

From Yen Press: A series of street slashings in Ikebukuro begins to connect total strangers: A teenage girl with no personality of her own; a beat writer for a third-rate tabloid; a teacher suspected of harassment; an informant based in Shinjuku and a headless rider straddling a pitch-black motorcycle! Meanwhile, the slasher continues to terrorize the night, all in search of "him"?