We've been getting a lot of good news in terms of new anime adaptions. New Jojo's, Rewrite, New Game, Full Metal Panic, Hibike! Euphonium, etc.
Even so, this is only a small portion of the shows that have tragically been left behind. Anime could be much better if it gave new sequel seasons or remakes to a ton of shows. In order of how much we need these sequels or remakes, these are the biggest tragedies in anime:
1. Negima/UQ Holder. This show needs a remake from the start of Negima to the very end this time following the manga instead of immediately veering off into filler, which should then flow naturally into an adaption of UQ Holder immediately afterwards. Negima should be in the top 10 of all anime but instead it's rotting in the basement. This is horrible.
2. Bleach. Bleach should be a top 10 anime, with one of the most epic and classic mangas of all time as its source material. The anime ended abruptly, just before the final arc of the manga, which means the show receives no satisfying ending or answers to any of the questions that remained looming all this time. Like, 'what is the nature of the Soul King and why did Aizen object to it so?' 'Who exactly is Ichigo and what is his origin?' 'What are the remaining bankais that weren't used during the espada war?' 'How do the remaining lieutenants fight who never got a chance to show their mettle at any previous point in the series?'
The questions go on and on. Without answers, the whole show feels bitter to the taste. The manga is providing these answers, albeit slowly, but the anime gives us no solace at all. This is a horrendous tragedy.
3. PapaKiki. PapaKiki's anime covers only its first book. The series has 18 books of material in it, all of it, no doubt, as heartwarming and heartbreaking and amazing as the original season. Talk about a lost opportunity. This series should be 50-100 episodes long, not 15. Even though we got to see the ending thanks to an oav, without context the ending isn't nearly as satisfying as it should be. How did we reach this point? Who knows. Not even the light novels are translated.
4. Index/Railgun. Both Index and Railgun have tons of material left. They're both super popular. This anime should continue for 100's of more episodes. So what the hell is going on? A fixture that is as permanent as One Piece in the literary world hasn't gotten a new animated entry in years.
5. Hayate no Gotoku. The greatest comedy manga ever seems to be approaching its ending, but the anime has skillfully managed to avoid all the best parts of the manga and ended ignominiously with a story about remote controlled cars.
6. The World God Only Knows. What came after the Goddess arc was kind of a mess, though it still deserves an anime anyway because even bad TWGOK is good compared to any other show. But the real tragedy here is the giant gap in the adaption between season two and season three. Because we didn't get to know the goddesses organically like in the manga, the third season felt rushed and confused. That gap desperately needs to be filled by a season four. The odds of this actually happening are 0%.
7. Haruhi Suzumiya. This may well be the most popular anime franchise of all time. So why, exactly, did the anime end when there were still five or so books left to adapt? Absolute madness.
8. Maria-sama ga Miteru. The climactic conclusion to Maria-sama exists only in the light novels. In the anime, Yumi still hasn't made Toukou her petit souer, nor has her Onee-sama graduated from high school. Neither of these pivotal touching moments in Yumi's life have been animated, so the whole series falls flat because this is what the whole series was aiming for from the very beginning. Those two moments are why the books were written. Why on Earth aren't they animated as well?
9. Haganai. The anime ended in a cliffhanger with Yozora running away from home. The books are already complete and have resolved all the loose ends. A fantastic story that mixed up humor, romance, social commentary and realistic human psychology deserves better than: "yozora ran away from home, the end."
10. Baka to Test. The light novels are over, with a satisfying ending that wraps up all loose ends. The anime ends in the middle of nowhere, having resolved nothing. Such a waste.
11. Claymore. The manga ended. The anime ended in filler that completely contradicts the entire theme of the manga. This anime is a travesty. The manga is nigh-perfect. Go back to before the filler began, and continue the anime all the way to the proper ending this time.
12. Gokukoku no Brynhildr. This anime should really be redone from the beginning, there was so much cutting of original content and addition of filler. This is such a great manga, and it was treated so badly by the anime. I feel so bad for it.
13. Akame ga Kill. The manga is nearing its climactic conclusion. Meanwhile, the anime came up with its own ending which nobody wants or cares about. The anime should go back to before when the filler began and tell the story correctly this time.
14. Akatsuki no Yona. The manga gets so much better once the dragons are collected. So of course, this is when the anime decided to end. Go figure.
15. Spice and Wolf. What happens when they reach the town in the north?
16. Miyuki. The manga has a fantastic finish full of deeply held feelings. It's a perfect love story. The anime never reaches the moment we've all been waiting for.
17. H2. While we're on the topic of Adachi manga, H2's anime is criminal. It ends right before the vital summer tournament that will determine everyone's lives begins.
18. Flame of Recca. The manga ended ages ago, so there's plenty of opportunity to give the anime a true ending as well.
19. Rurouni Kenshin. Same as Recca.
20. Kenichi. Same as Kenshin.
21. No Game No Life. We haven't even begun to delve into the intricacies of the fantasy setting of game world. There's still so many exciting things the anime hasn't reached yet. The anime ended in a ridiculous cliffhanger. Isn't it time?
22. Nichijou. The manga is ending soon. There's plenty of material left, so why not give the anime a proper ending too?
23. Sora no Otoshimono. The anime started deviating from the manga about halfway through. Go back from there and this time follow the story properly to the end, why don't you?
24. Dragon Ball. Dragon Ball Z got a fillerless redo called Kai. But the original Dragon Ball series did not get this Kai treatment. It desperately needs one.
25. Da Capo. The Da Capo III anime ended on a cliffhanger, explaining nothing. How great would this anime be if it got to show off the fullness of its plotline, the culmination of events that started in the very first Da Capo game?
26. Ranma 1/2. The Ranma 1/2 manga doesn't have a conclusive ending and the material is probably sub-par in quality compared to the beginning. Even so, to not have such a beloved classic animated from beginning to end, like Inuyasha received, is a horrible tragedy. The world remembers and loves Ranma 1/2 like no other series. They deserve this.
27. Shirobako. The anime had a nice ending, but can we really call that the end? Their careers have just begun. They didn't get to make their 7 lucky gods anime they've wanted to do since high school. Or was it college? In any case, the story just doesn't feel completed yet.
28. Grisaia no Kajitsu. The anime is pretty good, but it left a tragic amount of great material on the chopping board. Let's put that stuff back in.
29. Major. Two episodes to cover an entire arc of the manga is absurd. Major deserves a thorough and proper ending with, say, fifty additional episodes to cover the world series.
30. Outbreak Company. We barely got to know this series. It's way too short, and there are plenty of additional light novels. The girls are so damn cute. Can't something be done about this?
There are endless more anime series that deserve sequels, but I guess I can leave it at thirty tragedies for now. These are the mistakes that leave me up at night, crying into my pillow. I just can't forgive them for mangling so many works of wonder. This is indeed, collectively speaking, when you add up all the great series that never got animated in full even though they all had such great starts, the greatest tragedy in the world.