Games Series
- Obey Me!
- Occultic;Nine
- OCTOPATH TRAVELER
- Opus.COLORs
- Otome continue
- otona MUSE
- OZMAFIA!!
- Roll Over and Die: I Will Fight for an Ordinary Life with My Love and Cursed Sword!
- [Oshi no ko]
- Okami Kakushi
- Okiku Furikabutte
- Okasan to Issho
- Touch Detective Mushroom Garden
- Oshiri Tantei
- Ojarumaru
- Osomatsu-san
- Otogi Jushi Akazukin
- Onegai My Melody
- Onimai: I'm Now Your Sister!
- The Angel Next Door Spoils Me Rotten
- Octave
- Ojisama Senka
- Ozuma
- Otoca Doll
- Orient
- Alternative Girls
- Hortensia Saga
- ONGEKI
- Online Game
- Overlord
- Otome wa Boku ni Koishiteru
- My Next Life as a Villainess: All Routes Lead to Doom!
- Oretachin ni Tsubasa wa Nai
- Oretachi Majikou Destroy
- Ore no Imoto ga Kon nani Kawaii wake ga nai
- Ore no Kanojo to Osananajimi ga Shuraba Sugiru
- Onna no ko to Misshitsu ni itara XX shichau kamoshirenai.
- Osananajimi ga zettai ni makenai love-come
- Oshi ga Budokan Ittekuretara Shinu
- Ouran Koko Host Club
- Okinawa de Sukininatta Ko ga Hogen Sugite Tsurasugiru
- Onsen Musume
- Okami to Koshinryo (Wolf and Spice)
- The Royal Tutor (Oshitsu Kyoshi Haine)
- Osama Ranking
- Otoko wa Tsuraiyo
- Seraph of the End
- Oda Nobuna no Yabou
- Oishinbo
- Odoru Daisosasen Series
- Ongaku to Hito
- Ongaku Shojo
- Onigiri
- Onimusha