The girls win a lottery ticket to go onto an onsen in the mountains. There are some pretty nice fan-service scenes thrown here and there (nothing too explicit, of course, as always) and towards the end of the special Inugami-san and Nekoyamada-san have a little discussion when it comes to the feelings they share for one another that ends in their bonds getting even stronger by the end of the episode.
Of course, you can't really get too much character development in a 4-minute special, but I would say this is a pretty good ending of the series nonetheless. Especially considering what otherwise be the ending of the show not for this special: chapter 12 of the original anime: the girls holding hands while at a fireworks festival, the all-engulfing status-quo going almost unchallenged for the entire duration of the series.
If you are gonna watch this anime, you may as well watch this episode to get the full experience out of it. Especially considering it takes only 4 minutes to watch, lol.
