Groups
- oumi shouan 9
- oumiya 1
- ourakuen 11
- ourakutei 29
- ourakuza 13
- ourindou 3
- ouritsu buryoku koushi 2
- ousama no guntai 5
- out 6
- out of base 2
- out of mind 2
- out of service 2
- out of sight 49
- out of tune 1
- out of worker 1
- out-of-date 2
- outcount 1
- outdate 1
- outflow 3
- outgrow 1
- outrate 14
- outro 7
- outroad 11
- outside hours 3
- ouun 8
- ovacas 89
- over 4
- over all 1
- over drive 50
- over dynamics 3
- over easy 1
- over flows 5
- over heat 1
- over hundred 2
- over network unit-k 4
- over rice 1
- over3 7
- overall 3
- overcrowd 4
- overdose 84
- overdrive 10
- overflow 46
- overgrown generations 1
- overhead 3
- overheat 1
- overkill 7
- overkill comic 2
- overload 15
- overpants 5
- overrun 4