Heh. It does make a certain amount of sense for Seriko to exist! Her backstory checks out as another logical timeline that could have happened, and Nikki and Ami are rather cute together. Shame she didn't get to be the same age as Keiko and Hajime, but getting unexpected older siblings could be kind of fun too, I suppose.

Poor Ami never handles these reveals very well, though!

—doctorlit, bio-father in exactly zero timelines. He could be persuaded to adopt, though . . .