The alternative beginning for the TV version, but this adaptation stay closer to the original manga.
This introduce the characters better than the TV version 1st episode. For those who for some reason doesn't want to read the manga, I'd recommend watching this before watching the TV series.
As for voice acting part, I'm glad they change Ayu and Nina to Yui Horie and Kanda Akemi respectively. Yukino Satsuki and Omimura Mayuko is not that great in voicing the mc duo.
~Value~
For purist who like adaptation that stay true to the original source