Groups
- operetta 2
- operetta due 2
- oppai renmei kantai 2
- oppeke hei 2
- option 5 2
- orange caramel. 2
- orange gallery henshuubu 2
- orange isle 2
- orange shortcake 2
- orange yell 2
- orbit cactus 2
- orca 2
- oreharemon 2
- oren chin 2
- oreoreo 2
- organico 2
- orihika land 2
- orion 2
- ornithi5 2
- orrizonte 2
- orubara 2
- oruta bon 2
- osaka lucha libre 2
- osakana center 2
- osakana cookie 2
- osakana taikou 2
- osakana.factory 2
- osakanapakking 2
- osananajimi shikkaku 2
- osenkou 2
- oshiai heshiai dotukiai 2
- oshigoto no jikan 2
- oshioki club 2
- oshiroiro 2
- osonoya 2
- osos 2
- osunuya | shigaeya 2
- ota yuri 2
- otakaraya 2
- otaku biyori 2
- otama jacuzzi 2
- otamageddon 2
- otherwise 2
- otofu fire 2
- otomezaryuseigun 2
- otsukimi manbou 2
- ou no meiki 2
- ou-sama genkou kumiai 2
- ougi ranmaru 2
- ouji 2