The story takes place in Ert'Aria. The city is called "the city of treasures" and people are now busy preparing for a harvest festival. There is a mysterious power called Ale. If you gather Ale and crystallize it, it turns into a jewel. Once in every seven years, the harvest of Ale increases. The main character is Leicester. He is an item engineer and belongs to an adventurer group called Oasis. He also looks forward to the festival. A group of shooting stars fill in the sky in the year when the harvest of Ale increases. Yes, today is the day. Carina, Leicester's old friend, can't wait for it, so she takes him out into the town. At night, when Leicester and his friends have a party, a shooting star comes towards them! It passes them and falls down nearby. They rush to the venue and find a secret room. The room is filled with mysterious atmosphere and a girl sleeps in the bed. When Leicester looks at her face, she wakes up and says, "Oh, you're my father!" Her name is Minette and she leads Leicester and his friends to an adventure...