Hello guys

I'm planning on travelling Japan while doing some volunteer help exchange (Workaway, Helpx). The work is mostly helping with cleaning the hostel/Guesthouse and is completely without salary. So in exchange for helping out I only get free accommodation.
I'm sure some of you have heard of it before, therefore I wanted to ask you about the visa needed for such volunteer work? I have a hunch that visa waiver/tourist visa would be enough since It's not payed work, but I'd like to be absolutely sure before I plan my trip any further.
I would also like to hear about your workaway/helpx/wwoofing experiences!
Thank you~
