^ yeah, the two kids at the start and end are definitely sumire and yuri's kids (they both hinted at being pregnant around the same time so their ages and ran being older makes sense), it was just a timeskip type of chapter.
lol sakura looks so much like momo i thought she was a boy at first, but it's so sweet that their kids ended up being best friends too! and i'm guessing that them growing up together means sumire and momo ended up moving back to japan for a while, or at least visiting alot. and it seems like they move around a lot in general, which makes sense given their careers kinda