I'm looking for a manga that is two to three volume and it is complete the problem I don't remember the plot but I remember there were one of them that have a very long hair and they lived together and maybe but not sure one of them was an author or mangaka or something but not sure. The one with the very long hair is seme later on in the manga he will cut his hair. Please help me find it ..

Yasashii Kankei maybe?
The seme does cut his hair at the end, and is a writer.

http://www.mangaupdates.com/series.html?id=1719

That's really vague, but perhaps you could try giving the categories "Long-Haired Male Lead" and "Mangaka" a try. Sorry, I can't help you more, it would help if you had a few more keywords for a search or an image of the manga. Also, don't make multiple posts about the same thing...

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Kizuna ? Neither seme nor uke work as mangaka, but seme has long hair and cuts it later on.

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Yes that's it thank you