Zoo 06: The Search for Blood!

Speaking of Otsu Ichi's less often seen sides, this is the one I'd like to see more of.
I think this is only the second thing I've read by him that was designed to be funny. He's got a very offbeat knack for it.
The narrator is a 64 year old man who can feel no pain. He wakes up one morning covered in blood, and his horrible children, senile doctor, and gold digging wife discover a knife in his side, which seems to please them all immensely.
The senile doctor has brought enough of the narrator's blood to keep him alive until the ambulance comes, but has, unfortunately, forgotten where he put it. While they search for the blood, the narrator has plenty of time to solve his own murder.