| Title ▴▾ | | | Released ▴▾ | Rating ▴▾ (▴▾) |
| Ore-tachi ni Tsubasa wa Nai ―――under the innocent sky. | | | 2009-01-30 | 8.57 (468) |
| Our Life: Beginnings & Always | | | 2020-11-16 | 8.33 (419) |
| Our Life: Now & Forever | | | 2025-11 | 8.15 (23) |
| Otome Riron to Sono Shuuhen -Ecole de Paris- | | | 2013-07-26 | 8.14 (395) |
| Omertà Code:Tycoon | | | 2013-12-27 | 8.08 (67) |
| Omertà ~Chinmoku no Okite~ | | | 2011-04-22 | 8.03 (145) |
| Our Wonderland | | | 2024-04-05 | 8.02 (16) |
| Okujou no Yurirei-san | | | 2012-03-30 | 7.95 (1299) |
| Olympia Soiree | | | 2020-04-16 | 7.93 (469) |
| Oyako Rankan | | | 2012-09-14 | 7.90 (368) |
| Ochiru Part Tsuma - Toshishita Otoko to no Jouji ni Oboreta Hate ni... | | | 2023-08-04 | 7.88 (123) |
| Ore-tachi ni Tsubasa wa Nai AfterStory | | | 2010-07-30 | 7.84 (159) |
| Ourai no Gahkthun: Shining Night | | | 2013-08-23 | 7.82 (42) |
| Once in a Lifetime | | | 2021-06-19 | 7.82 (316) |
| Omoide Kakaete Ai ni Koi!! | | | 2021-09-24 | 7.79 (149) |
| Ore no Shita de Agake | | | 2002-11-29 | 7.78 (30) |
| OPUS: Longmai Changge | | | 2021-09-01 | 7.72 (78) |
| Otome Riron to Sono go no Shuuhen -Belle Epoque- | | | 2016-05-27 | 7.71 (163) |
| Otome wa Boku ni Koishiteru ~Futari no Elder~ | | | 2010-06-30 | 7.70 (113) |
| Our Red String | | | 2023-10-13 | 7.68 (50) |
| Onii-chan, Asa made Zutto Gyutte Shite! Yoru Made Motto Ecchi Shite! | | | 2019-06-28 | 7.66 (129) |
| Otokano ~Otouto no Kanojo ga Bunkei de Tsuyome!?~ | | | 2022-05-27 | 7.65 (75) |
| Oni Kantoku to Ore no Kanojo ~Joyuu no Tamago ga Oni Kantoku to Nikutai Kankei o Musunda Riyuu~ | | | 2012-07-31 | 7.64 (61) |
| Ore no Kanojo wa Taninbou ga Ki ni Naru You Desu. ~Karakai Jouzu na Hentai Kanojo to no Seishun Swapping wa, Ore no Kakure Seiheki o Kaikashi Hidaika Sasemashita~ | | | 2020-07-31 | 7.64 (192) |
| Oba Netori ~Otto no Shiranai Midara na Kankei~ | | | 2016-04-01 | 7.64 (139) |
| OBSCURA | | | 2023-05-01 | 7.62 (21) |
| Ochiru Hitozuma | | | 2011-12-23 | 7.62 (858) |
| Our Fantastic Wonderland | | | 2022-09-30 | 7.61 (8) |
| Otome ga Tsumugu Koi no Canvas | | | 2012-03-30 | 7.61 (263) |
| Otome no Ken to Himegoto Concerto | | | 2023-07-28 | 7.60 (55) |
| Omoi o Sasageru Otome no Melody ~Afureru Omoi o Shirabe ni Nosete~ | | | 2017-11-24 | 7.60 (43) |
| Ore o Hoshigaru Tsuma to Gibo | | | 2021-03-26 | 7.59 (131) |
| Oyako x Shuffle! ~Natsuyasumi, W Oyako no Icha Icha Houimou~ | | | 2018-12-21 | 7.59 (160) |
| Okaa-san ga Ippai! | | | 2009-12-25 | 7.58 (67) |
| Ouka Sengoku! ~Nobunaga-chan no Koishite Yabou!?~ | | | 2010-10-29 | 7.58 (53) |
| One → Shota ← One | | | 2020-11-27 | 7.57 (80) |
| Ouka Sabaki | | | 2017-02-24 | 7.54 (531) |
| Omae no Kaa-chan, Ii Onna Da yo na. | | | 2018-09-21 | 7.53 (219) |
| Onee-san x Shuffle! ~Tomodachi no Onee-chan no Ecchi na Karada.~ | | | 2017-12-22 | 7.53 (106) |
| Ore no Imouto ga Konna ni Kawaii Wake ga Nai. Happy End | | | 2013-09-26 | 7.53 (20) |
| Onii-chan, Kiss no Junbi wa Mada Desu ka? Ecchi no Junbi mo Mada Desu ka? | | | 2017-02-24 | 7.52 (146) |
| Ore no Sugata ga, Toumei ni!? Invisible to Suuki na Unmei | | | 2020-03-27 | 7.52 (223) |
| Ojou-sama wa Sunao ni Narenai ~Daisuki o Kimi dake ni~ | | | 2018-03-30 | 7.51 (37) |
| Oathbreaker | | | 2019-02-14 | 7.51 (18) |
| Oshikake Kanojo wa, Ore no Sewa o Shitai | | | 2019-11-29 | 7.50 (34) |
| Ore wa Tsuma Killer ~Tsuma 5nin, Musume 5nin, Oyakodon Okawari!~ | | | 2011-11-18 | 7.50 (123) |
| Onna Ninja Azusa vs Orc 3 ~Injuu-tachi no Oukoku~ | | | 2019-06-28 | 7.49 (26) |
| Oh Yuusha yo, Itte Shimau to wa Nasakenai! | | | 2015-08-28 | 7.49 (94) |
| Oku-sama wa Moto Yariman 2022 | | | 2022-12-24 | 7.49 (94) |
| Onii-chan, Asa made Zutto Gyutte Shite! | | | 2018-05-25 | 7.48 (279) |