Japan used to have a fabulous program called 'PTP' ie People to People. It was administered through a Japanese bank. Might be worth checking out. Is the international peace organization SERVAS still operating? It too, would be worth checking out. The former leaned more toward homestays, while the latter was completely flexible.
Good luck HT.
I am done. The local

The best way to meet the locals is to ask if you can join an evening at a local English language school for an impromptu lesson exchange. I've done this with my own English lessons and they almost always turn out to be the best lessons for all parties involved. To get the ball rolling, the teacher can ask students to think of questions they'd like to ask the visitor. Alternatively, the visitor can ask the locals questions too. The best way to round this off is to go out for drinks afterwards.