In the past, you had to start over again, but he did make a forum post a bit ago that he was working on an updater for the next one.
Not sure if thats still true though, because there were some story changes to the prologue (namely Shino, from what I understood. Her story was started when it was a "haha, funny sex game" and it doesnt fit the tone it ended up being, so he's redoing her intro quests)