Madhouse
(founded 1972)
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The Animatrix (two segments)
Batman: Gotham Knight (segments 4 and 6)
Cardcaptors (Cardcaptor Sakura)
Death Note
The Girl Who Leapt Through Time
Gunslinger Girl
Metropolis
Monster
Ninja Scroll
Paprika
Paranoia Agent
Perfect Blue
Reign: The Conqueror
Summer Wars
Supernatural: The Animation
Tokyo Godfathers
Trigun