This was definitely axed, it was so rushed that it went against the whole atmosphere of the entire manga. Not to mention that afterword by the author: "I'm sure their lives will casually move along, but this is where this story ends", sounds a little too much like "there was more to come but unfortunately this where I had to end it." Also the introduction of the wolf (fox maybe?) -girl and Kumika's sister who saw almost no screen time. I doubt they would have introduced them into the main cast only to end the manga a few chapters later.