From the introduction:
This adventure tells the tale of forbidden love that stretched across social boundaries, time and death to the ruin of all others. This story is of a prince named William that had everything but true happiness and of a common girl known as Erised who craved a fullness of life, fortunes untold and a handsome husband.
Erised, the daughter of a farmer, was an idle hand and always danced instead of helping out like her siblings. So, during a particular horrible drought, her father sold her off to a dance troupe in the capital as the farmers had too many mouths to feed.
William was the first born of the sitting king and abided by his father’s rule. This all changed when one night William went to attend a ballet at the King’s Dancehall and was lovestruck by the lead ballerina. The lead dancer was Erised who had flourished within the dance troupe and had become a star in her own right. When William watched Erised dance, he was entranced. When Erised met William after the show, they fell for each other, but it was not to be. William knew he could never marry Erised, his father would never allow it, and so they commenced a secret affair between them. William even managed to build a secret tunnel between the castle and the dancehall so that he could meet Erised undetected. As a sign of their love, William bought Erised a boiled candy in the shape of a love heart that Erised treasured.
Unfortunately the two lovers were caught. Erised was banished from Burgwin and William was forced into an arranged marriage. Erised was shattered, she was so close to everything she ever wanted, only to have it all dashed. It was then that a being approached Erised in her dreams offering her to be with William for eternity if only she could open a magical bottle within the grounds of Burgwin City. When Erised awoke, she spied the bottle discussed in her dreams, and diligently went about following the instructions.
Erised was tricked by a water demon and when the bottle was opened within Burgwin, an endless quantity of water vapor rushed out of the bottle. It was so quick that Erised did not have time to react, and before she knew it the valley where Burgwin lay and everyone in it was drowned as the water vapor quickly turned to water. A magical dam was also created by the cursed spell and kept the water contained in the valley and as an ironic twist of fate, the demon used Erised’s treasured candy as the only key to unlock the seal on the dam.
The demon kept its word though, and Erised and William were not killed like the others. Instead, William was transformed into a flying fish and Erised into a waterfowl. They were together but also forever apart. As part of the curse, the couple can dance together on one day of the year, when William flies out of the lake and joins with Erised in a mesmerizing ballet set.