| Oriakos | 2024-07-23 | - |
| Ori, Ochi, Onoe | 2006-08-10 | 6.30 (46) |
| Ori no Naka no Paraphilia -Seirei ni Ochita Shoujo-tachi- | 2010-01-30 | - |
| Ori & Bluewyn: Nurseroom | - | - |
| Ori | TBA | - |
| Ori | 1998-08-28 | 6.10 (6) |
| Orgullo y Repito | 2024-08-11 | - |
| Orgel ~Kesenai Melody~ | 2000-03-24 | - (2) |
| Orgel of Orpheus -Other Comb no Senritsu- | 2011-02-13 | - |
| Orgel of Orpheus -Orpheus no Ginkoto- | 2010-08-14 | - |
| Orgasm Treatment | 2023-02-12 | - (3) |
| Organized Crime | - | - |
| Orga Fighter Ayana -Departure- | 2013-07-05 | 6.70 (11) |
| Orfej: Eho Aida | 2026-05-10 | - |
| Oreteki Jitsu wa Konna Bamen ga Mite Mitakatta!! | 2007-02-01 | - |
| Oretachi, Lolikko, Dai Koubutsu! | 2006-12-01 | - |
| Oreritsu Saimin Gakuen | 2019-10-18 | 6.10 (22) |
| Orekore! | 2007-12-31 | - (2) |
| Oreiro Ganbou ~Ore to Arisu no Kankei wa~ | 2011-08-26 | 5.80 (10) |
| Oreimo Plus | 2010-12-31 | 6.20 (127) |
| Ore-tachi no Tatakai wa Kore Kara da! | 2021-07-14 | 5.80 (6) |
| Ore-tachi no Sekai wa Owatteiru. | 2017-11-09 | 6.50 (251) |
| Ore-tachi no Futsuu ja Nai Koi no Hajimarikata | 2018-05-05 | - |
| Ore-tachi ni Tsubasa wa Nai ~Prelude~ | 2008-06-28 | 7.30 (213) |
| Ore-tachi ni Tsubasa wa Nai AfterStory | 2010-07-30 | 7.80 (194) |
| Ore-tachi ni Tsubasa wa Nai | 2009-01-30 | 8.60 (588) |
| Ore-tachi ga Shinda Natsu, Tenshi no Ita Mikkakan. | 2011-08-13 | 6.60 (15) |
| Ore-sama no RagnaRock | 2010-10-28 | 6.70 (47) |
| Ore-sama Kingdom: Ikemen Kareshi o Get Shiyo! Moe Kyun♥School Days | 2012-12-13 | - (2) |
| Ore-sama Kingdom ~Koi mo Manga mo Debut o Mezase! DokiDoki Love Lesson~ | 2011-11-23 | - (3) |
| Ore-sama Gakuen | 2011-01-11 | - |
| Ore*ji ★ **do Flash | 2007-04-09 | - |
| Ore(♂) wa Maid(♀) ni Saserarete, Karen na Cupid ni Moteasobareru | 2024-12-20 | 6.20 (20) |
| Ore wa, Shokushu Breeder ~Kisei Shokushu de Naedoko-ka Suru Onna-tachi~ | 2017-12-08 | 6.00 (21) |
| Ore wa Tsuma Killer ~Tsuma 5nin, Musume 5nin, Oyakodon Okawari!~ | 2011-11-18 | 7.50 (132) |
| Ore wa Shoujo Mangaka | 2012-02-23 | 7.30 (36) |
| Ore wa Nayuki o Wasurenai | 2001-08-12 | - |
| Ore wa Kimi no Seiriyou Napkin o Nametai | 2014-08-17 | - (1) |
| Ore wa Kanojo o Shinjiteru! ~Enkyori Ren'ai no Susume~ | 2007-07-27 | 7.10 (107) |
| Ore wa K*na Da | 2020-04-28 | - |
| Ore wa Jukujo Kyouai Shugi ~Yokkyuu Fuman na Hitozuma Hodo Ochiyasui~ | 2017-10-27 | 5.70 (13) |
| Ore wa Hime Bushou o Haramasetai! | 2020-06-26 | 5.80 (9) |
| Ore wa Gibo ni Netorareru ~Watashi-tachi mo Misetsukete Yareba Ii no yo...~ | 2021-05-07 | 6.40 (84) |
| Ore to Vita to One Room | 2012-08-12 | 5.30 (6) |
| Ore to Senpai no Christmas ga Ooisogashi na Ken ni Tsuite. | 2019-12-26 | - |
| Ore to Saeko-san to Netorare Mail | 2011-10-21 | 7.40 (143) |
| Ore to Omae ga Ai ni Tsuite Kataru dake | 2019-02-16 | - (3) |
| Ore to Okaa-san no Haramase Skinship | 2016-10-28 | 6.20 (21) |
| Ore to Nakayoshi Shimai no Inma na Himitsu ~Imouto ni Shinu hodo Kiraware Nagara Ane to Sex Suru Kimyou Doukyo Seikatsu~ | 2021-08-27 | 6.80 (62) |
| Ore to Mahou no Koibito | 2004-04-16 | - (4) |