I don't know how they're gonna do future seasons of this show without Mariko. She was the heart of the series.
I'm on the fence about watching further seasons, leaning more towards not watching.
Partly because I was happy to watch a limited series that told a good story and got out.
But a major part of that is Mariko was the heart of the series like you said, Anna Sawai was incredible, and now she's not in it. What am I coming back for? A bad accent from Anjin and a stoic performance from Hiroyuki Sanada?
If they knew they were gonna be a hit and switch from limited to returning, they definitely would have changed the story and not killed her, just seriously injured her or something.