OakElementaler
 OakNotice Me, Lily!
 Oak AzzraelItsuka, Kasanariau Ashita e
 OasisOnsoku Hishou Sonic Mercede...
 ObaaMinami no Shima ni Furu Yuki
 Obaa-sanMashou Megane
 ObabaTanetsuke Mura ~Hakudakugam...
 Obara AnzuHare Nochi Kitto Nanohana B...
 Obara KarinHare Nochi Kitto Nanohana B...
 Obara NanaoUchi no Ichizu na Tsuma ni ...
 Obara NorioMaou no Ingu
 Obara Shin'ichiUchi no Ichizu na Tsuma ni ...
 Obara ToukoSixty Nine
 Oba-san
 Obase MiyukiShikkan ~Hazukashimerareta ...
 Obata NatsumiRen'ai Multiple!
 Obata YuuHakui no Gohoushi
 Obayashi KeitaTsuisou no Augment, Tsuisou no Augment
 Oba YukariKoshitsu Byoushitsu, Nurse no Obenkyou Ouyou Hen...
 OberNamaiki Dark Elf 3 Shimai g...
 OberarztWeinsgranat
Oberreit
 Obihiro RaichiBitch Gakuen ga Seijun na H...
OboroTrue Treasure
 Oboro
 OboroDemonion ~Maou no Chika You...
 OboroInmyouji
 OboroUtawarerumono
 OboroTenka Touitsu Koi no Ran
 OboroTaimanin Asagi, Taimanin Asagi Gaiden ~Chao..., Taimanin Asagi 2, Lilith-Izm02 ~Nakadashi/Har...
 OboroFuyu no Otogibanashi
 OboroTenma Shoujo Rena -Hatsujou...
 OboroMitama ~Shinobi~
 Oborogasaki ArareJunjou Karen Freaks!
 Oboro IoriUnmei Senjou no Phi
 Oboro / Oboro TokoAku no Onna Kanbu "Kono Wat...
 Oborosawa YukarikoOborokomachi
 Oborotsukiyo no KimiGenji Koi Emaki
 Oboro YachiyoToki no Kizuna Sekigahara K..., Toki no Kizuna Hanayuitsuzuri
 Oboshiro DaiyaHimawari no Kyoukai to Naga...
 Obsidia RavenDead Tide VIII: New Poon
 Obuchi MinamiSchool Days, Cross Days
 OcchanStep×Steady
 OcchanAyakashibito
 OcelotThunder Claps!
 Ochiai MadokaSeiso na Aniyome wa Ore Dak...
 Ochiai MisakiSoredemo Tsuma o Aishiteru
 Ochiai TomoyoriHitomebore
 Ochi AkariKansen 5 ~The Daybreak~, Kansen Ball Buster
 Ochiba TooruNegapoji ~Onii-chan to Yoba..., Negapoji Fandisk ~Hitotsu Y...