I think we had a discussion way back in the comments heap about this before too. Growing babies = need bean paste, so having too many stalks sucks all the paste out and the yukkuri dies. Baby yukkuris don't have much paste so you get the picture.
Well, apparently not... seeing as to make babies, it takes paste (probably also the reason why pregnant yukkuris commonly eat more, to make up for the loss). Baby yukkuris, like here, don't have much paste themselves, so there isn't enough for either so both die.
Basically, mister told them no babies. Then mister went on an extended business trip and came back to find Marisa forgot that this is his place and not their's, and that they had babies. So he's getting rid of them.
I went through and re-checked what was in story A; it's all correct now. A few strips were missed or classified as something different first time round. These were: post #19823, post #19840, post #19861, post #19873 in that order at the beginning of the series. Please ensure you do those, and upload those first to keep it in order.