- Opération : Monarque
- orange - Tome 3 (VF)
- orange - Tome 4 (VF)
- Orange 1
- Orange 2
- Orange 3
- Orange 4
- Orange 5
- Orange 6
- Orange Crows, Volume 1
- Ordinary Girl In A Tiara
- Ordinary Girl, Society Groom
- Orient Volume 1
- Orient Volume 10
- Orient volume 11
- Orient Volume 2
- Orient Volume 3
- Orient Volume 4
- Orient Volume 5
- Orient Volume 6
- Orient Volume 7
- Orient Volume 8
- Orient Volume 9
- Orion
- Os Curiosos
- Os Segredos Que Ela Carregava
- Ossan Idol!, Volume 1
- Ossan Idol!, Volume 3
- Ossan Idol!, Volume 4
- Ossan Idol!, Volume 5
- Otaku and the Struggle for Imagination in Japan
- Otaku Elf Vol. 1
- Otaku Elf Vol. 2
- Otaku Tōkyō isshūkan
- Othello
- Otherside Picnic 01 (Manga)
- Otherside Picnic 02 (Manga)
- Otherside Picnic 03 (Manga)
- Otherside Picnic: Volume 1
- Otherside Picnic: Volume 2
- Otherside Picnic: Volume 3
- Otherside Picnic: Volume 4
- Otherside Picnic: Volume 5
- Otherside Picnic: Volume 6
- Otherworldly Munchkin: Let's Speedrun the Dungeon with Only 1 HP! Volume 1
- Otherworldly Munchkin: Let's Speedrun the Dungeon with Only 1 HP! Volume 2
- Otherworldly Munchkin: Let's Speedrun the Dungeon with Only 1 HP! Volume 3
- Otherworldly Munchkin: Let's Speedrun the Dungeon with Only 1 HP! volume 4
- Otome Mania!! Vol. 1
- Otome Mania!! Vol. 2
- Otomen 1
- Otomen 10
- Otomen 11
- Otomen 14
- Otomen 15
- Otomen 16
- Otomen 17
- Otomen 18
- Otomen 2
- Otomen 3