Mh...so the line-up so far is:
Takagi Family:Takagi Fujimaru (aka "Falcon") - Miura Haruma
Takagi Ryonosuke (Fujimaru and Haruka's father) - Tanaka Tetsushi
Takagi Haruka (Fujimaru's younger sister, suffers from kidney failure) - ?
Takagi Kanako (Fujimaru and Haruka's mother, Ryonosukes's wife, deceased) - ?
Newspaper Club:Kujou Otoya (Fujimaru's childhood friend, leader of the newspaper club) - Sato Takeru
Asada Aoi (Fujimaru's classmate, she has a crush on him) - ?
Anzai Mako(to?) - ?
Tachikawa Hide - ?
Terrorists:Orihara Maya (Fujimaru's new Biology teacher, terrorist) - Kichise Michiko
Jack Damon (terrorist/assassin/killer, former SWAT member but got kicked out due to his blood lust) - ?
Third-I (PSIA):Director Sonoma (Director of "Third-I" the secret department of the PSIA, boss of Fujimaru's father) - Matsushige Yutaka
Hosho Sayuri (?) (agent of Third-I, older sister figure) - Katase Nana
(Kirishima?) (agent of Third-I) - Yoshizawa Hisashi
I'm going by the manga characters since the official site does not list all of the roles yet and I might be mis-reading some of the names in Japanese...? It is to be expected that the story and visualization of the drama will be quite different from the manga (TV censorship since the manga is REALLY gory and maybe a little too perverted for the Saturday slot...).
A comparison as to the 'style' of the drama I've come accross is the American hit series "24". Bloody Monday is said to be similar to that.