If you're expecting a solid conclusion to the anime with this, prepare to be gravely disappointed. This is essentially the fanservice episode of the anime, and it doesn't even do that good a job of that. The bulk of the episode revolves around the girls essentially taking pictures of each other and running around an in-door pool and just dicking around in general, which isn't that bad if you actually like these characters. I wouldn't have minded some development on the sister's relationship here, but we really didn't even get that. Watch this only for full completion of the anime.