Hmm, I'm surprised you heard that about Osaka, there seem to be lots of disabled people here in comparison to other Japanese cities I've been to. In one particular area of Osaka, around Tanimachi and Tennouji, I used to see many disabled people, so I always assumed that there was a special school in the area.
Cram schools would probably also cater for students of special needs - I teach a young down syndrome boy occasionally at my language school (one of the Big 4), my school specially caters for him.