Visa extension not in passport?

I recently got an extension for my Japanese visa (spouse visa). When I picked up my new Zairyu Card I also had them to give my passport in the process.
Now I've seen that no changes have been made in my passport (i.e., there is no new sticker for a new visa or extension or any such thing). All I have is my new Zairyu card with the new period of stay.
Now my question is: When I leave Japan the next time and then come back (with the original visa expired), will immigration not check my passport for a valid visa? Is it really ok If I can only show them the new Zairyu card? I always thought that for immigration only the passport is relevant.

Thanks in advance for your answers!

Cheers
Matt

They never check the stamp.

When I leave Japan the next time and then come back (with the original visa expired), will immigration not check my passport for a valid visa?

When leaving, you should show them your zairyu card. On entering, they don't care, at all.

When checking into an international flight to Japan, some airline staff may be looking for the stamp, but you will be able to convince them that you are a resident by showing your zairyu card.

I - a foreign resident of Japan - have not had a stamp in my passport for years. Do they even still put them in there?

your passport alone is not sufficient to show your resident status in Japan. you need to have a set of your passport and your zairyu card. (i.e. zairyu card corresponds to the stamp you want to have on the passport.)

Um, I think there are some concepts being confused here.
1) you have a big sticker on your passport with your INITIAL visa that allowed you to come to Japan. That was a 1 time entry visa in order to claim your residency status.
2) When you first arrived in Japan you got a zairyu card with your initial residence status. Eg spouse. And a duration.
3) now you live in Japan and you change/extend your residence status. Letfs say you change from spouse to a work status (letfs say in the humanities category). You get a new zairyu card with your new status and the new duration. Same applies if you extend the duration.

BUT in your passport nothing changes. Your one time entry visa has been used up years ago when you first came. In order to proof that you now live in Japan you have your zairyu card.

An other PP referred to gstamp in passporth. I think what she/he was thinking is the typical stamp you get gevery time when you enter / leave Japan. Regardless if you are a tourist or resident. My old passport is full of these stamps. But in recent years I think they stopped putting stamps in the passport.