The story takes place in a trading city Ert'Aria. Leicester Maycraft is an item engineer belonging to an adventurer guild "Oasis." One night, he is at a party with his friends to see a meteor stream on the rooftop of a chapel. One meteor grazes them and hits the steeple of the chapel. There he finds a secret room and a sleeping girl. The girl wakes up and says "You must be my father!" The encounter with the mysterious girl brings an unexpected adventure to Leicester.

Short extra anime "Isshoni Bath Time". The main characters taking a bath will be displayed three dimensionally on 3D TV. Normal 2D versions are also available.

Announced in the live program on Niconico douga. The story will be unrelated to the TV series. Fanservice promised.