Language, Study Guide, Children's Book Series
- Always 3 chome no Yuhi
- orange
- [Oshi no ko]
- Ookami kodomo no Ame to Yuki (Wolf Children)
- Okasan to Issho
- Treat of Reincarnation
- Curious George
- Touch Detective Mushroom Garden
- Oshiri Tantei
- Ojarumaru
- Osen
- Osomatsu-san
- Odekake Kozame
- Onegai My Melody
- Ghostbook
- Opanchu Usagi
- Omae Umasodana
- Only Yesterday
- Ojamajo
- Ookami-san Series
- Okami Shojo to Kuro Oji
- The Diary of Ochibi-san
- Orient
- Orix Buffaloes
- Olympic
- Orange Page
- Online Game
- Ore no Imoto ga Kon nani Kawaii wake ga nai
- Ore monogatari!!
- Ohoka Echizen
- Omoi, Omoware, Furi, Furare
- Omoide no Marnie (When Marnie Was There)
- Osama Game
- Omotesandou Kouko Gassyobu!