O

• Obake Life
• Okusan
• One Missed Call
• One Piece
• Onegai Twins
• Onepunch-man
• Ookami Lover
• Orange Marmalade
• Ore to Hero To Mahou Shoujo
• Oshiire kara Ai o Komete
• OTHELLO
• Otogibanashi no Fude
• Otome no Iroha!
• Otoyomegatari
• Oumagadoki Doubutsuen
• Owari no Seraph