The official picture for the DiaLover’s anime has been released~ and I have also found out the seiyuu roles for the anime, which are the same as the game.
Hikaru Midorikawa as Sakamaki Ayato
Yuuki Kaji as Sakamaki Kanato
Daisuke Hirakawa as Sakamaki R/Laito
Kousuke Toriumi as Sakamaki Shu
Katsuyuki Konishi as Sakamaki Reiji
Takashi Kondo as Sakamaki Subaru