Daemons have been released, and Yumiko asks Koyomi to help her vanquish them, unaware that the only magic Koyomi canperform is summoning washbasins.

A trip to the water park turns chaotic. Misa seeks to find the source of the virus that brought the Daemons. The ladies prevent a possible disaster.

The past and present stories are told together. In the present, Koyomi travels back in time. In the past, the reason for Guibarthez's pursuit of the Kerykeion is revealed. Misa resolves to fight Guibarthez.