Parodies
- obake no holly | holly the ghost 1
- obakeidoro 5
- oban star-racers 22
- obey me one master to rule them all 3
- obi wo gyuttone 3
- oboro muramasa | muramasa the demon blade 64
- occult academy | seikimatsu occult gakuin 93
- occultic nine 68
- ocha nigosu. 2
- ochame na futago 5
- ochamegami monogatari korokoro pollon | little pollon 1
- ochikobore fruit tart 19
- octopath traveler 29
- oda nobuna no yabou 95
- odd taxi 64
- odin crown 3
- odin sphere 84
- odoru daisousasen 9
- odyssey 1
- oemojisangjui | lookism 4
- off 2
- oh edo rocket 2
- ohayou spank 1
- ohsama sentai king-ohger 39
- oide yo mizuryuu kei land 15
- oira uchuu no tankoufu | mighty space miners 1
- ojama yurei-kun 1
- ojamajo doremi | magical doremi 1248
- ojisan to marshmallow 3
- ok k.o. lets be heroes 287
- okami 68
- okhotsk ni kiyu hokkaido rensa satsujin jiken 2
- okinawa de suki ni natta ko ga hougen sugite tsura sugiru 4
- oku-sama wa joshi kousei 8
- okujou no yurirei-san 7
- okusama ga seito kaichou 7
- okusama wa mahou shoujo 8
- okusan 54
- ol shinkaron 1
- ole tower 7
- olive the other reindeer 2
- oliver and company 23
- ollie and scoops 1
- omae umasou da na 1
- omaera zenin mendokusai 1
- omakase peace denkiten 3
- omakase scrappers 2
- omakase trouble angel 1
- omamori himari 14
- omaneko 2