This OVA of Mirai NIkki explores the ending of the original series in further detail. A very simple 30 min OVA that probably used around 5 minutes of recycled footage from the last episode.
All in all, it's a fanservice ending to the Future Diary story and the story of Yuki and Yuno. The writing is around the same level as a fairly competent fan-fiction, and the content is fairly fan-fiction-like as well.
The art and animation is a bit of an improvement upon the original series given that it's one single OVA episode aired around a year after the ending. Fairly fluid and clean, with some characters' designs cleaned up a bit as well.
The story is split around half-half. Half of it is a brief look at characters' lives in the third world where the Future Diary games never occurred. Which frankly I don't really care about, given that most of these characters never made an impression on me in the first place. And half of it is the third world Yuno finding a way to second world Yuki. The manner in which this occurs is fairly non-sensical, but not completely outlandish, and certainly wraps up the ending in a slightly more satisfying manner than the original. Mostly because the original ending was completely unexplained. Unfortunately, similar to the original series, if you just think about this episode a little bit, the consequences of people's actions here, as well as their motivation, are quite illogical, and the whole thing kind of crumbles.
Despite that, it's still worth watching, You've come this far into the series, what's 1 more episode. Just don't look for anything more than a well-animated fanfic level ending expansion, and this shouldn't disappoint you.
