Giving birth at home country and returning to Japan

Hey everyone,

Me and my wife live in Japan, we both hold residency, she went back home and she will give birth there.

Now I will go back later to be with her but we plan to return when the baby is about 6 weeks old. We will stay for less than 90 days (~85 ish ) because I will finish my work and return home permanently.

The issue is I know the lengthy process of obtaining the CoE and then visa and then the residence card at the airport , which in this case is not applicable because of the short time.

So I was thinking of applying for a tourist visa for my child (and of course both of us will be with him), this would grant us 90 days (hopefully). But I don’t know if this might work.

Btw, I know the healthcare here is covering most things (so does back home but we prefer to be there with family).

I would like to hear your advice.

Thank you.