Anything involving the Child Welfare Agency taking Rihoko away after finding her real mother or Masane's body slowly breaking down due to overuse of the upgraded Witchblade qualifies.
Probably one of the most heartbreaking moments is in the penultimate episode where Masane eats a meal Rihoko made for her before heading off to her final battle (and almost certain death), only to discover that she's lost her sense of taste.
Hisae Iwaoka's One Shot "White Clouds" does it in an unusual way. Told from a dog's point of view, it narrates the life of an old couple and their dog. The grandma has passed away time ago and the old man and his dog realize that the same fate is coming closer to them. If by the end of the 16th page you haven't felt moved at least, you seriously need to start looking for your soul.
