Helping young children learn Japanese

Hi! My husband and I will be moving to Japan for six months on a nomad visa next year. He is fairly fluent in Japanese while I've only just started and we will continue to learn and work on it before we move.
My big concern and where I'm looking for advice is based around our children. Our oldest will be newly 5 and our youngest will turn 3 while we're out there. How do we expose them to the language to help them get a good base? Are there classes or daycare we could place them that are bilingual?
From what I've seen, spots can be limited and since I don't have a job I worry daycare won't take them since it's not necessary.
What do y'all recommend to get them socialized and exposed to the language other than daily life? Will park trips and play time be enough? Are there tutors for children to help them learn the language?
The goal is to give them a base that we can expand on as our japanese fluency grows and continue to use the language when we return to the united states. I guess I'm just not sure where to even begin with this aspect of the move.

by Nikiboomboom23