Serie includes 180 albums .
O ni ichi ~yantachitoissho
Onee-chan ni Ecchi na Koto Shicha Ikemasen! 5
Oneechan ni Ecchi na Koto Shicha Ikemasen!!
Onii-chan-tachi to Issho
Ookami-san to Ohime-sama
Oshaku
Otokonoko tte... Sugoi -Soleil Hen-
Otouto-tachi no Touma Oukoku Haneiki
Oujo-sama to Kagyaku Seiheki na Danna-sama 3
Oujo-sama to Kagyaku Seiheki na Danna-sama 4
Rhodolite no Mangekyou
Rouroutari