Where to buy cheap used bicycle?

Hi all! I’m moving to Osaka (Toyonaka-Suita area) in October and I’m looking for pretty much the cheapest bicycle I can get my hands on. Can anyone recommend any inexpensive secondhand bike shops? Or even better- is anyone looking to get rid of their bike?

I’m just looking to get something for casual daily commute. Bonus points for cheap used helmets as well!