A lot of Anime is inspired on a previous work, either be a Manga, a Show, a Novel, and sometimes the material is so much that it truly can´t be all put on a 12-24 chapters or they reached the original material. Either way, these series are incomplete.
I´m not talking About the cases were the anime productions invented an enemy or a history arc in order to give it a closure(Hellsing, Full Metal Alchemist) Since the anime story was clearly finished, nor when they stopped right after a story arc ended and didn´t touched the next one or gave hints about it (Monster Musume) Since still the story up to that point can be finished in a successful way.
What I am talking is that the anime itself doesn´t have a feel of closure, the main story is not finished, the characters arc are unfinished or barely untouched and or the characters were left without development. Similar to a “But our fight still continues” (Like it was said on Shirobako) But in a Frustrating Way.
For those series…Here it is my Top 5.
Also: Yes there will be some spoilers, although I will try to be the most vague possible.
#5- World War Blue.
The Re-imagination of the 80-90´s Console Wars between Nintenrudo (Nintendo) And Segua (Sega) in a fantasy Setting! The anime had good art, so good that in some way affected the manga it came from (Gear´s Outfit changed to a more similar to the Anime), it had funny and endearing characters , and an history that besides being full with video games throwbacks, was getting more and more exciting!
But… Litle to that was explored, The series ended just when the world was expanding, the Nintenrudo forces was about to make a move, All the world of Consume was noticing Segua´s New Champion Gear (Sonic), and the characters had little development, with Opal we never sought who was that person on her memory or Gear never got his revenge against Nintenrudo for example. The series just ended when the main event was about to happen.
This series stay so low on the list because the anime was made only in the form of a three Chapter special, so there is only so much terrain one can cover in that little time, but still…Lots of things were unanswered, and unless you bought the manga, you won´t know.
#4- Rokka: The Brave Six Flowers.
When the Demon World resurrects and tries to destroy the world, the goddess of Fate will call 6 heroes and grant her the power to go in order to defeat it, the thing is that on the reunion point…There was Seven, So one must be a fake, and maybe an enemy who only wants to kill the true six heroes!
Now While the story arc has ended (they discovered the fake one and they could get out of the place) , it ended with the opening statement that they have to continue…Which it wouldn´t be so bad if it weren´t for the fact that the main enemy (The Fiends) are finally making a move instead of being passive in that regard. Also the fact that they added a character on the final chapter doesn´t help things much.
Still this is on the 4th position due to the it is basically a “But our fight still going” and there is a chance that a second season might come.
#3- Saint Seiya: The Lost Canvas.
Saint Seiya: Lost Canvas tells the story of Tenma, the Pegasus Saint of the past generation of Saints and how he will join to Athena´s Army , who is her childhood friend Sasha, against Hades , who is none other than his best friend Alone.
The Anime is quite loyal to the manga , and incredible good! (Both of them are), maybe it is because Shiori Teshirogi (The Mangaka) was prior to that a Shojo Mangaka, which make that the psicology of the characters were more complex than the original Manga of Saint Seiya.
Anyway, the Anime ended on a truly cliffhanger moment, The Hades Castle has been destroyed at the cost of Tenma´s Master Life (…), Alone/Hades and Pandora has left to the Lost Canvas with a big smile on their faces because big part of Athena´s Army has been annihilated with only some Bronze, Silver and Gold Saints at her disposal and Tenma, who has always been more depressive (Unlike Seiya who is happier) feels like a waste and a weakling who has the curse that anybody who knows him has to die.
Of Course Sasha/Athena gives a speech about how if they still have hope and never give up, they will see the light again, and such. But is not enough for our Pegasus Saint.
As you can see the anime left in a turning point of the story, I remember when I ended seeing that chapter I was so hyped to know what will happen next that i googled it in order to know if there will be a Season 3…Which I sadly come to know that there it won´t. Man I felt crushed! The Good thing is that the manga is being officially localized here in México, so I can buy it and know what will happen (And its awesome!)
This one stays on the number 3 because, if you read the past paragraph, you can see the frustration when the things aren´t resolved and are left in a critical state. But Still that feeling that there is still more to know is not as strong as the next two
#2- Nanana´s Buried Treasure.
When Yama Juugo Moves in to the “School Island” Nanaejima, he encounters the ghost of a beautiful girl on his apartment. It looks like she was killed in there when she lived there, but besides that when she was alive her name was Nanana, an amazing adventurer who has collected treasures from all over the world and has hide them in the island, in order for the people to go and live and adventure in order to encounter them!
Nanana´s Buried Treasure is an Anime I started Just because I had some free time on that moment, and man I was hooked to the series! It helped me with the adventure itch I had since Getbackers Anime! The way they had to solve the puzzles and dangers in order that Juugo and the rest of the adventure club could obtain the treasures was something really good! I liked all of the characters, from Juugo ,w ho is a kind hearted pervert, Nanana the Cute flan loving ghost, and all of the others members of the cast.
But then it ended it´s run… And nothing was explained or revealed. We still don´t know who killed Nanana and don´t have a clear clue to it, nor when the big and final fight between the president of the adventure club against both juugo and Tensai ( A detective girl) will happen, nor a lot of the mysteries behind the past of most characters than little snipstes. Of course , the series continued on the Light Novel, but for the people who either can´t obtained it or aren´t interested in them. The story ended and it resolved nothing in anything, and the only thing they got was a fight against the previous habitant of Juugo´s Apartment (And for that he knew Nanana) and that´s it. So Yeah… This is Number #2 because is a Good adventure Anime that it didn´t resolved anything of it´s premises.
#1- My Litle Monster.
Shizuku is a nerd girl who focues only on studying in order to obtain a work where she will gain lot´s of money, she has not much interest on her life besides that. Until one day she get´s to know Haru, a trouble boy who doesn´t attend to school, after some events he starts going to the school in order to see her and be with her. These two polar opposites will be in a story were friendship, love and all the problems (both real and mental) of the relationship will be in!
I Started reading the manga and then lefted it after a few chapters (Mostly because I forgot it´s name :P). When I noticed there was an Anime for it I started watching it, and I loved it! The humor, the characters, the reactions, everything! And then it ended the anime And…
… Nothing was solved! Shizuku and Haru likes each other, but they aren´t together still, Natsume still hasn´t accepted her feelings for Micchan, Sasahara is just there, we won´t know what will happen on the picnic day, and to add more salt to the injury (And teh reason this is Number #1) that the Ova they made after it it has nothing to do with the story!
Lucky For us our Good friend Protonstorm has given his thumbs up on the manga!
Anyway. Those are my top 5 of series who has that kind of thing. If you have a personal one or want to add something feel free to put it in the comments!
Yes I put that last one just because :P