It was serialized in Shueisha's Weekly Shōnen Jump from February 2011 to July 2012, with its chapters collected into eight tankōbon volumes.

The series follows the story of Shion and Emma to complete the magic ritual "Magico" to seal away the power of Echidna, a dreadful and extremely powerful magic dormant inside Emma's body.

Emma, a country girl, first came to the city to start a new life after having been isolated since early childhood.

But for some reason, when she entered the city all the young men and even the king tried to forcibly marry her.

Later on he explains to Emma about her history and how she is the legendary Echidna, a power born every 500 years so devastating that in the wrong hands, could mean the destruction of the world.