An amusement park that Keiichi and Belldandy once went to together is closing down. They decide to go to it again on the closing day for a long overdue outing together. Meanwhile, an excess of happiness in the world is threatening to make the Goddesses unnecessary. It turns out that the source of the excess happiness is Belldandy. Urd and Skuld have to figure out what is causing Belldandy's happiness to overflow before it goes out of control and eliminates the need for Goddesses to exist in this world.