Ryuu wa Tasogare no Yume o Miru (Dragon Transformations)

Note: This is an expansion of an old post from 2012. We've revised it and added lots of images, including some unavailable anywhere else online.

Also known as The Dragon Dreams of Twilight, this two-volume manga stars Kiya, a lab-raised teenager who can turn into a dragon. He is forced by his handler T.J. to work for a secret organization that destroys monsters. 

Here's his first transformation:

Here is a brief scene for those who like tails: 

Next up, Kiya's longest transformation scene. How nice of the artist to spend five lovingly detailed pages on it!

Later on Kiya partially transforms at an awkward time:

At the end of the first volume (and beginning of the second), Kiya and T.J. run into some werewolf-like monsters. Kiya transforms, and then, at T. J.'s prompting, goes into berserk feral mode:

Only the first chapter of volume 2 was translated, and since I couldn't find raw scans online, I bought the book and scanned the TF scenes myself. You'll have to forgive my scanner's inferior visual quality. One more thing: I bought the German translation of volume 2, since it was cheaper than the Japanese original. So if you know German, you're in luck.

While on a cruise Kiya starts transforming:

Shortly afterward Kiya runs into another werewolf-type monster:

Back on land,  Kiya undergoes an unexpected transformation at home:

And finally, here is a partial TF:

And that's all. What a pity this manga was never adapted as an anime!