ah, awful dads....... they have so much in common! Kiryu will be a better dad for both of them one day.

That sounds great to me! Kiryu would absolutely love having a younger sibling, once he figures out what to do (like does he have to feed her? buy her birthday gifts?? how do kids work.) Maybe they can have each other's names written down somewhere but haven't really been too compelled to seek them out or are like "no way I'd ever actually talk to or find this person" and then they see their names on Retrospec like OH.... NO...... and the awkwardness and hilarity starts there?