Does it make any sense? Not really.
Does it matter? No, because you're having way too much fun watching it to really give a damn.
Although the anime version of Grisaia no Kajitsu remains one of the worst adaptations I've ever seen in my life, Rakuen on the other hand is one of the very best ones. The difference in level of faithfulness to their respective visual novels is so unbelievably big that I don't even know how to put it into words. The pacing is solid, the production value is great and very little noteworthy content is left out. Overall, it's a brilliant adaptation from start to finish.
The anime can be divided into two parts. Episodes 0-4 (yes, zero; don't miss the double-length special episode, it's mandatory) cover the Grisaia no Meikyuu visual novel and takes place almost entirely as a prequel story about Yuuji's past. It is a quite dark and depressive tale containing physical abuse, rape and death among other things. It is one of the most serious parts of the Grisaia trilogy, and it gives you an excellent insight into Yuuji as a character. You'll realize that he is quite likely the most in-depth harem protagonist ever written when all is said and done.
After that, episodes 5-10 instead cover the Grisaia no Rakuen visual novel, which in contrast to the rest of the series is one of the most exaggerated, absurd and just plain ridiculous stories that I've ever had the pleasure of reading, but it's also those same exact reasons that make it so incredibly entertaining. It is effectively the inverse of Kajitsu, as the original story is about Yuuji having to save all the girls, whereas Rakuen is about the girls having to save him in return. Now that may just sound like more of the same, but I kid you not when I say that Rakuen is *completely* different. It's essentially a different genre altogether. Rakuen almost feels like a Hollywood action film, containing logic-defying car jumps, helicopter chases, submarines and pink .50 caliber sniper rifles, as well as some highly questionable sci-fi elements such as human-computer integration and cloning technology. If Mission: Impossible was an anime, this would be it. All-in-all it's an absolute nutcase of a storyline, but it's so much fun that despite its absurdity everything just ends up feeling awesome to watch. There are countless points throughout the anime where you'll find the flow of events being blatantly illogical, but it won't make you feel annoyed. Instead it'll just make you laugh and/or feel excited for what curveball the anime is going to throw at you next. Another boon with this is that the nonsensical story turns out incredibly unpredictable since literally *anything* can happen in it, no matter how unlikely it may be. And as the cherry on top, Rakuen also has one of the most ridiculous and far-fetched endings in anime history, but given the progression of the story... dammit it just feels so *right* somehow.
As far as the characters go... I'll just say this: taking the entire series into account, the character cast of the Grisaia trilogy is and always has been my number one favorite one of all time. No exaggeration. Seriously, Yuuji is arguably the best harem protag ever, at least in terms of writing and persona, and after you've seen his backstory you might also argue that he's perhaps the only one who legitimately *deserves* to have his harem already. And the girls... they just have so much charisma, all of them. How could you not love them? Makina has one of the most outstanding personalities and speech patterns you'll ever find, Amane is like a mother to everyone else, Sachi is the most badass maid of all time, Yumiko is a natural-born commander, Michiru just has waifu tier written all over her and Kazuki is without a doubt my favorite Onee-chan character ever. Even the side characters like Asako, JB and some others are quite spectacular by themselves.
The animation is as good as it ever was (the only part which even Kajitsu's adaptation got right after all), but the soundtrack of Rakuen is just plain better all-round. It's upbeat and energizing, and has numerous memorable instrumental tunes containing lots of violins combined with fast-paced music. The anime's opening theme is also fantastic, albeit not quite as legendary as Rakuen's visual novel opening (seriously go YouTube it if you haven't, it's amazing).
Anyway, overall what you have is a story which I highly recommend you to not take too seriously. Or rather you can take it seriously, but only up until Rakuen starts (episode 5) because from there on out it's a joyride of insanity all the way to the end. If you try to make a detailed analysis of the story as a whole, then what you have is a plot with more holes than a golf ball... in other words; don't try to analyze it. You'll be the only one who'll suffer from it. Instead, just lean back and tag along for the ride, and you're in for a ton of fun.
Now if only all visual novel adaptations could be this good..................... and yes I'm still looking at you Kajitsu...
