Music Series Beginning with O
- OUR HOUSE
- Ouran Koko Host Club
- Ouroboros
- Outbreak Company
- Over 30
- Over Drive
- Overlord
- Ozuma
- Scenes from Awajima (Awajishima Hyakkei)
- Seraph of the End
- The Oblivious Saint Can't Contain Her Power (Mujikaku Seijo wa Kyomo Muishiki ni Chikara wo Tarenagasu)
- The Ogre's Bride
- The Royal Tutor (Oshitsu Kyoshi Haine)