I did change my mind about the day of thunder. The timeline has been unaltered. This is after the Kami Togashi returns to the Celestial Heavens. I have plenty of ideas for demonic and non-demonic encounters, and what not. And with the Spider Clan around it gives other options.
As far as the players know the plot is a simple kidnapping. You'll see what it will lead to as the game goes on.