I'm looking for manga like Bokurano or Deep Love. That means optimistic start, seemingly cheerful characters, bright world, birds, blue sky and so on. "Happy beginning" in two words. But as story evolves, world around characters starts to crumble, everything goes wrong, as soon as you think it can't be any worse, there is new mishap. This shouldn't happen in one instant, but in a steady progression.

Preferred:
Seinen or Josei
5 or more volumes for completed
10 or more volumes for ongoing
No yaoi or shounen ai, but ok if it's LGBT in non yaoi/yuri
Japanese manga (not manhwa, manhua), doesn't matter if it's translated or not.

SaiKano
Milk Closet and Alien Nine
Higurashi no Naku Koro Ni - this isn't consistently true over the entire series, but the first few arcs at least work

Saikano is a great example, but i've already seen anime.
Alien 9 and Milk Closet are confusing. I was full with solving plot puzzles, no time for sympathy.

Anything else? Preferably not an adaptation of game/novel, but original manga.

Is it something like fruits basket? or maybe Gakuen alice? dunno but I feel those two looks so cheerful at first to me, but as the story goes on, many 'dark past' revealed...

I think pretty much all Suenobu Keiko's works

(Too bad you don't want shounen-ai because I think Let Dai would meet your requirements rather well.)
Maybe Clamp's X? It fits I guess, but the manga has been on hiatus forever. The Anime is complete though. But it's not supposed to be in a realistic world, and even though you don't say it in your desciption I kinda get the feeling that you'd prefer a realistic story...

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I've heard that School Days is like that, but I haven't confirmed it myself.

Last edited by C117 at 3:13 pm, Nov 18 2011

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Second School days and I recommend Chrono crusade - anime, I'm not very sure: Ga-Rei, Valkyria chronicles - anime - does not go entirely downhill but it is pretty close.

Thank you all! Your suggestions make a good list, though not a single entry comply with all preferences.

Fruits Basket, Gakuen Alice, X, Suenobu Keiko's works - all shoujo.
Let Dai - korean and shounen ai.
School Days is based on a game and i've played that eroge.
Ga-rei - shounen.

But i'm going to look through all these titles.

If you play games, I don't know if you already played it and/or are interested, but to me the most downhill stuff I ever saw is Chaos Head, route B. I don't think something can go as bad as that.

Unluckily, I really can't think of a manga with all the features you want. Maybe Narutaru (same mangaka as Bokurano), but I still have to read it all.

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