Talk:Volume 2, Chapter 13/@comment-3261234-20130905192509/@comment-30764484-20130906003701

I did some searching, and apparently it's quite possible for twins to be born even a couple months apart. The world record for longest time between with both surviving is 87 days. Yui and Ui are also 87 days apart. Now, before you get too excited, this record was set this year, so it's not a reference to that, but still, it's possible!

Given that they are actually identical (aside from hair), and that if they were two years apart there should be a much more visible difference between them, especially in the flashback scenes (a three year old and five year old are very different, for example), I think they actually are delayed twins!

I wonder if we could get an official word on this, it's a shame I don't speak/write Japanese.