Gotta say, this is one of the hidden perks of being an avid anime watcher: special episodes. Like definitely, one of the things that made Jackie Chan movies and the older Pixar movies so memorable were the gag reels, and, for anime, BD/DVD specials are exactly that.
11eyes was a pretty mediocre anime. The story was pretty bland, the characters weren’t too interesting, the fantasy aspect got old really fast, and the special powers were extremely run-of-the-mill. The only things it had going for it were a pretty stellar production and that yandere twist I won’t describe any further in case you haven’t seen it. However, the plot was serious enough that makes this kind of special episode very enjoyable.
No reason to review the episode, since it’s purely fanservice and, if you’re interested enough in this franchise in the first place, you’ll watch it regardless. Even if you haven’t seen the anime, the seriousness of the original series is easily recognizable and should make the gags entertaining.
NyaaTorrents link for 720p BD rip subbed by [Derp]
I also found a short special for To Aru Kagaku no Railgun while browsing the new releases, but it was nothing great, just fanservice in the original sense of the word. However, I am pretty curious about exactly where the name “Ekaterina” comes from. As far as I know, it was first Yoshida Kazumi’s dog’s name in Shakugan no Shana, and it’s been used in Railgun as Kongou Mitsuko’s boa constrictor’s name. I guess it’s a running JC Staff joke?