- o_m(localize)
- oakwood academy of spells and sorcery
- object control ~escape by mysterious specimen rape and birthing~
- oblivious
- oblivious x
- obscene medical records of a married nurse
- obscurasoft
- obscurite magie: the city of sin
- ochiru hitozuma
- octopussy_company
- octotap
- oculus rift
- oda non
- odbear studios
- odes
- odin sphere
- odyssey of gianna
- off shot
- offbeatr
- office 5656
- officer chloe - operation infiltration
- offside
- oh so hero!
- ohiyosoft
- oide yo! mizuryuu kei land ~kazoku to sukebe na theme park~
- oiran ichimi
- ojoy studios
- okayama figure engineering
- okonomiyaki
- old town rpg like thing
- ole
- ole-m
- omega force
- omega labyrinth
- omega labyrinth life
- omega labyrinth z
- omega quintet
- omega star
- omega zodiac
- ona-ken!
- onahole
- onamonatope
- onasis
- once ever after
- one hell of a week
- one man army
- one night one murder
- one piece
- one piece pirate warriors
- one piece pirate warriors 3
- one punch man
- one x shota act: smash boy
- one-hand-free-studios
- one-up
- onechanbara
- onechanbara z2 chaos
- onee-sama productions
- oneechanbara
- oneechanbara origin
- onegai teacher
- onelegninja
- oneone1
- oneshota swordplay act: hagokoro
- onigokko!
- onii kiss: oni chan where's my kiss?
- onii-chan asobo
- onimasyumaro
- only furry 18+
- onlymyrailgun
- onmedia
- onmyouji in the otherworld: sayaka's story
- onomatope*
- ooparts
- open forum
- operation lovecraft: fallen doll
- opiumud
- oppai academy big, bouncy, booby babes!
- oppai academy: big bouncy booby babes!
- oppai cafe
- oppai games
- oppaiclick