All I can say is WARNING: If you've enjoyed the original series don't bother watching this. Only watch this if you like nostalgic moments and want to be reminded of this series.
In short the whole episode feels like a love letter to fans who miss the show with some old jokes thrown in. Hence the nostalgia.
Full review (SPOILERS INCLUDED):
Ano Natsu special/OVA takes place 2 years after the original series. Where we learn that the main characters are already in their final year of high school and graduating soon. Sounds like a great plotline right? Wrong.
To begin, Ichika & Lemon-senpai are missing from the episode.
Not entirely true. Actually they only make cameo appearances.
Lemon rejoined the MIB in episode 12 so it makes sense if she doesn't appear at all in the OVA. But for Ichiko, if you watched the last scene of Episode 12 you notice that in the school festival film Ichika is saying her lines while wearing the jacket Kai's sister bought for her. So that means she did come back to earth shortly sometime after Episode 12 ended because the film was made during the summer and shown immediately at the school festival after summer vacation ended. But here we are shown that Ichiko never came back at all during those 2 years and everyone is still moving on. So what happened? Sadly we never got an answer.
Next, instead of discussing how their lives have progressed after the events of Episode 12 (And why Ichika is missing), 8 mins into the OVA Kai decides to watch one of his old film reels and from there we spend the next 10 mins of the 23 mins episode observing the lives of the main cast ONE DAY before they made their movie. So I guess like most animes this OVA is a prequel? (Surprise, surprise)
As I've mentioned the old film reel part turns the entire episode from Sequel to Prequel. We see reruns of old jokes like Lemon-senpai tricking everyone into getting drunk and Ishigaki's sister calling her husband an idiot.
Soon after the reel ends (And we're left with only 5 mins of screentime), Kai meets up with the rest of the old cast (Ichiko still missing of course) and they hang out like old times. In the final scene we're taken to space where we (finally) see a cameo of Ichiko looking out the spaceship window excitedly (presumably because she is coming back to earth)
As I've said its a pure nostalgic episode with no plotpoint at all. Meant to be a love letter to fans so I give it a 6 because whie I am happy to see Ano Natsu again I would prefer if made something more plot significant or didn't make this episode at all.
