Hmmm.  I kind of want it to be further in the future so that there are new captains, but all that designing might take too much time and I don't want to get bogged down with having to make too many characters.  So for now I'm going to say we're starting with the division captains at the end of Bleach and will slowly replace them over time.  

So I'd say that we'll start off maybe thirteen or fourteen years after the events of bleach so that the two children are old enough to learn about shinigami powers but won't be too strong. Would like to see them have story arcs that parallel those of our own characters.