Ojamajo Doremi
Ojisan to Marshmallow
Ojou to Banken-kun
Okane ga Nai
Okashi na Tensei
Okinawa de Suki ni Natta Ko ga Hougen Sugite Tsurasugiru
Okiraku Ryoushu no Tanoshii Ryouchi Bouei
Okusama ga Seitokaichou!
Okusama wa Joshikousei
Okusama wa Mahou Shoujo
Olympia Kyklos
"Omae Gotoki ga Maou ni Kateru to Omouna" to Yuusha Party wo Tsuihou sareta node, Outo de Kimama ni Kurashitai
Omae wa Mada Gunma wo Shiranai
Omamori Himari
Onara Gorou
Onee-chan ga Kita
Onegai My Melody
Onegai Teacher
