Mede Shireru Yoru No Junjou
As well as Sakura Gari
I have to agree with Ivis' choice of Mede Shireru. That's because of the story's setting and the age and occupation of the characters. If it took place in the modern era, it would be illegal. Proceed carefully if you find that sort of stuff upsetting.
Bronze. o_õ BY FAR.
I love Zetsuai, which is the prequel, and it's also angsty, but Bronze takes the melodrama oscar by kilometres.
angstiest manga you've ever read?