I have mixed feelings about this. Ao is a hard-working character (not to Rentaro levels, but still), but it seems so unreal to me that it ends that way. He was struggling so hard for her beloved one, and for him to end up dead from a fatal wound from her is a bitter pill to swallow I still can't accept. The irony in all of this only makes "that" scene more sickening than it is. Midori's death was surprising, but it was bound to happen sooner or later, but Ao's "death" is something I didn't expect, or at least not before he reunited with Nezumi for one last time.