[Shiroi Hane]

Amazon seems to agree:

最終第13話とTV未放映エピソードを収録

- http://www.amazon.co.jp/dp/B001QD6CFM/

As does the official anime site:

第十三幕「仁、デレる」・テレビ未放送エピソード1話 収録

- http://www.nagisama-fc.com/anime/dvdcd/dvd7.html

I won't insult anyone by including the web translations, but both mention an untelevised episode.