The Kotonoha Sisters and the Legend of Lysant Island

After winning a trip to the everlasting summer haven Lysant Island in a raffle, the Kotonoha sisters arrived to days of rain that made for anything but a vacation! And at a festival being held to clear the rain during their stay, the sisters get caught up in a mysterious incident...! A miscellany of enemies attack the sisters, including the Goddess of the Sun, Demon of the Rain, and giant creatures! Will they ever be able to enjoy their everlasting summer island vacation?