The Goddesses and their sisters take a camping trip to "My Summer Vacation Mountain." When the sisters uncover another dimension at the shrine gates, they meet an older version of Neptune. Will they find their way back home, and, more importantly, are two Neps better than one?

Dayan, who cannot read the language of Ars (Earth), sets off on a journey to find Zitan, who has gone off to the north, in order to have him read the letter.