Origin: Spirits of the Past
Overtake!
Onmyoji
Onihei
Otoboku: Maidens are Falling for Me!
Otaku no Video
Over the Sky
Our love has always been 10 centimeters apart.
Orange
Oretachi ni Tsubasa wa Nai: Hadairo Ritsu Kyuuwari Zou!?
Orb: On the Movements of the Earth
Otome wa Boku ni Koishiteru: Futari no Elder The Animation