What anime character has the most tragic background story?

Akemi Homura from MSMM

I don't know, really a lot of characters have a tragic past in every manga I read o in every anime I've watched. For example in ángel Beats everyone had a really hard life, o also in Pandora Hearts many characters have a dramatic story, but these are just examples. I really don't know who to choose.

Itachi Uchiha ((Naruto Shippuden))

Alois Trancy from Black Butler.

In my opinion, Madame Red from Black Butler...

Not the most tragic but still depressing kiritsugu Fate/Zero (or Kotomine also works for this)